Setting mail programs - key principles for setting any email client. Mail server for beginners. Configure DNS zone Anti-virus check of investments

Installing your mail server, as a rule, does not cause special difficulties. A large number of finished instructions are available on the network. Literally one team, and the 25th port is ready for work. It gets fun when the letters sent to return, and the recipients complain that the messages do not reach. Here you already want not to want, but you will have to look for causes and delve into technology.

Who sends letters

Today, the ability to bind your domain to the service is offered by many web services. Especially popular posting mail on Gmail or Yandex. All messages will go through the SMTP server provided by them, the proven service provider will form all the necessary headings and signatures that will allow you to go through any spam filter. But this option is not always possible. For example, an organization has a large number of users, you need special settings for mail, inaccessible in cloud services. Or your server is used with the portal, CMS or online store from which you want to send messages.

By default, all PHP applications are used to send mail the mail () function, which, in turn, sends them through the local SMTP server described in PHP.ini.

Sendmail_path \u003d / usr / sbin / sendmail -t -i

Or in a virtual host:

PHP_ADMIN_VALUE SENDMAIL_PATH "/ USR / SBIN / SENDMAIL -T -I -F [Email Protected]"

And although there in 100% of cases is written by Sendmail, in fact it can be simlink, and mail refers postfix or exim. To send mail from the application, you can choose one of three options:

The engine itself sometimes allows you to specify an external SMTP server (in default settings or via plugin, in WordPress this WP Mail SMTP or Easy WP SMTP). It is enough just to specify the account data, and all problems are solved.
Using a gasket program that emulates the location of the local SMTP server and sends messages via the mail account on a third-party server. SSMTP is very popular here.
Using your email server. Of course, it will be necessary to configure it, but more configuration features.

We are interested in the last option. We will analyze how to break through the antispam technology and is guaranteed to deliver the message to the recipient. You will not filter spam. This is the topic of another article. You will choose PostFix and Exim as an experimental SMTP server, they are popular on hosting, simple and understandable in the settings, although the main questions will concern all SMTP servers.

How not to get into spam

Fighting with spam is the headache of all mail administrators. And recently recently the reverse side of the medal: spam filters are literally visible. Therefore, the spam in the incoming mail is practically absent, but the normal messages constantly disappear somewhere, customers and management are nervous, and it is necessary to make sure that the message came to the addressee. And after installing the SMTP server, it will be more likely to be concerned about the messages at all at least reach out. In particular, to assess the settings, you should see if letters in the boxes of the main mail systems Gmail, Yandex, Mail.ru are delivered. Typically, at this stage, the first difficulties appear, and it is necessary to solve all the problems personally.

The postal services use a multi-level spam filtering system, and even their own technical support does not know about the principles, even their own technical support. And each service has its own priorities. Although usually some hint about the reason for the shortage is contained in the response letter of service. Also, the Mail-Tester.com service helps in the analysis of the reasons, it is enough to send a letter to the address specified there and then after analysis, get the result and list of problems. Some of them can be checked and deciding without yet configuring the SMTP server.

The fight with spam gave rise to many technologies. The oldest one of them is the BlackList, which includes all IP and domains engaged in the spam sending, there may be open relays, proxy and dialup addresses used for remote access (that is, they theoretically should not send mail). There are such BlackList in different ways. DNSBL (DNS Blacklist) uses black lists in DNS format, which is easy to poll. Today there are many databases, not all of them are popular and are used. The problem is that there is no list for a particular mail service, how many and what they interview are a mystery.

Domain names, like IP addresses, today can be "favor". There is a chance that they used the service of sending messages or the host, placed on it, was hacked and sent spam. Accordingly, they may well get into some kind of DNSBL and be a problem. Mail.Ru discarded letters from one IP precisely because he was in one of these half-selling lists, hitting there in 2010. Moreover, Mail.Ru did not even bother to check the correctness of the SPF and DKIM. The case has shifted only when IP was removed from the black leaf.

You can check the IP or domain yourself, send the DNS request to the selected DNSBL server using the DIG utility:

$ host -ta site.EX.dnsbl..Ex.dnsbl.org Not Found: 3 (NXDOMAIN)

But it is more convenient to use online services that are checked immediately in several bases. IP can be checked in DNSBL.Info (59 bases) or WhatismyiPaddress.com (72 bases), domain, in addition - in MXToolbox.com (107 bases), spamhaus.org or multirbl.valli.org. If suddenly a domain or ip will be in the list, it is better to write down to support and remove your address.

Correct DNS

Upon receipt of the message, the remote SMTP server analyzes first of all its heading. The mail program sends only From, To, Date, Subject and X-Mailer. They are generally understandable and simply indicate from whom and where to go. The rest of the header is formed both the SMTP server and the application that is sent. This, by the way, should also be considered, because letters sent via Telnet can leave, and with RoundCube - no, just because they have a different heading. RoundCube, for example, applies its HELO / EHLO based on the server_name or localhost variable if it is not defined. Therefore, sometimes you just need to ask it clearly:

$ rcmail_config ["SMTP_HELO_HOST"] \u003d "example.org";

The same applies to self-written php scripts.

When transmitted, the letter will take at least two SMTP servers, each of which also adds something from itself into the title. First of all, each server adds its Received: From. Read them better from bottom to top. The lowest message is the sender's server, the most upper - the recipient server. Although actually servers may be more, it is especially true when working with large service providers, which, having received a letter, move it further, or when used on the SMTP proxy path. You can use the service from Google to analyze the message path, which will show all SMTP servers in clear form, the SPF, Dkim and DMARC tests (about them further).

Receive headlines are different, although there are general rules. Typical looks like this:

Received: from server.example.org (helo \u003d server.example.org) by st15.provider.com with ESMTPS (Exim 4.80.1) (Envelope-From )

Here the message was obtained from the server called Server.example.org, has IP 1.2.3.4, the same name was used in Helo greetings, received its EXIM 480.1 servers ST15.Provider.com. Message sent to S. [Email Protected] Having accepted such a header, the SMTP server begins to check the data. Perses domain and IP on DNSBL databases. Checks the presence of MX record from the domain. MX is initially used to search for mail servers serving this domain, its presence confirms that the domain sends mail.

Further, it makes the reverse IP name resolution through the reverse DNS request using the PTR record. That is, he recognizes the server with which name must be at the address from which the message came. This behavior was laid in RFC 2505 from February 1999 Anti-Spam Recommendations for SMTP MTAS. And although it has long been recognized that the reverse zones are not a sufficient condition for the unequivocal identification of the sender and often lead to errors and delays, they are still supported. Therefore, they must coincide, otherwise the message at least will receive minus in the ranking, and in the worst case will be discarded.

In our example, Server.example.org must be fixed for IP 1.2.3.4. DNS record looks like this:

1.2.3.4.in-addr.arpa. In Ptr Server.example.org.

IPv6 uses IP6.arpa. In principle, it is not necessary to know about the features of PTR, as PTR, with a rare exception, only hosting the hosting provider sets up. And if it does not suit, then you just need to contact support. You can check PTR using the query:

$ Dig -X 1.2.3.4

In fact, the PTR record after deploying VDS may indicate the technical domain submitted by the provider, like SRV01.Provider.net, in the VDS HostName template included as Ubuntu1604 (changes in / etc / hostname), in Helo / Ehlo SMTP server writes in general LocalHost .localdomain, and the letter comes from the Example.org domain. The probability of delivery of the letter under such conditions will rapidly approach zero. Although some services mark such inconsistencies as an error and conduct a complete check.

Especially I would like to pay attention to that VDS usually has two IPv4 and V6. Therefore, all of the above applies to both versions, since the letter to one server can go on IPv4 and deliver, and the other prefers to use IPv6, and the letter may not reach the recipient. At the same time, a lot of providers, providing IPv6, absolutely do not bother with the PTR record setting, and checking it returns an error. But Google, for example, prefers IPv6 and immediately discards the letter if the PTR does not match the name of the server. In the response service of the service it looks like this:

Continuation available only to participants

Option 1. Join the site community to read all the materials on the site

Membership in the community during the specified period will open you access to all the materials of Hacker, will increase your personal accumulative discount and will accumulate a professional Xakep Score rating!

, | |

Running site or web application, users tend to configure both the mail server for the processing of incoming and outgoing mail. However, often the presence of its own mail server is a serious vulnerability for the project according to a number of reasons. In general, the configuration and support of the mail server is a complex and time-consuming task that takes a lot of time.

This manual covers many reasons that can keep you from using the mail server, and will also help you choose alternative options.

Complexity of mail servers

An ordinary mail server consists of a variety of software components, each of which performs a specific function. Each component should not only have a fine setting, but also interact with the rest of the components to provide the full functionality of the mail server. Due to the large number of "movable" components, mail servers are quite difficult to install.

Components needed to each web server:

Message forwarding agent (MAIL TRANSFER AGENT, MTA);
Message Agent (Mail Delivery Agent, MDA);
IMAP server and / or POP3.

Spam filters;
Antiviruses;
Webmail.

Some software packages include the functionality of several components immediately. In addition to software components, mail servers require a domain name corresponding to DNS entries and a SSL certificate.

Consider the necessary components in more detail.

Agent sending messages

Message forwarding agents (or MTA), machining SMTP protocol traffic (Simple Mail Transfer Protocol), is responsible for:

sending user messages to an external MTA (that is, to another mail server);
getting messages from external MTA.

Examples of MTA: PostFix, Exim, Sendmail.

Message delivery agent

The message delivery agent (or MDA), which is sometimes referred to as a local delivery agent (Local Delivery Agent, or LDA), extracts messages from the MTA and places them in the mailbox of the appropriate user.

There are a huge set of mailbox formats (for example, MBox and Maildir). Each MDA supports a specific mailbox format. The mailbox format defines a method for storing messages on the mail server, which, in turn, affects the use of the disk and the speed of access to the mailbox.

Examples of MDA programs: postfix and dovecot.

IMAP and / or POP3 servers

IMAP and POP3 are the protocols used by mail clients, that is, any software for reading and extracting messages. Each protocol has its own difficulties; This article discusses some of their key differences.

IMAP is a more complex protocol that allows, among other things, support several customers to connect to an individual mailbox simultaneously. Email messages are copied to customers, and the original remains on the mail server.

A simpler POP3 protocol moves email messages to a mail client computer (as a rule, the default is the user's local computer).

Examples of IMAP and POP3 servers: Courier, Dovecot, Zimbra.

Spam filters

The purpose of the spam filter is to reduce the number of incoming spam or unwanted mail in the mailbox mailboxes. To achieve this goal, spam filters apply spam detection rules that take into account various factors (sender of the message, content and much more), which allows you to evaluate the message. If this estimate exceeds the so-called SPAM LEVEL, the message is recognized as spam.

Spam filters can be applied for outgoing mail. This feature can be useful if the user's mail account was hacked: thus you can reduce the amount of spam transmitted using this mail server.

An open source filter is a popular open source filter.

Antivirus

Antiviruses are used to detect viruses, trojans, malicious programs and other threats in incoming and outgoing mail. ClamAV is a popular open source antivirus.

Web Mail (or Webmail)

Many users need a webmail. Web Mail (in the context of working with the mail server) is an email client, accessible to users via a web browser (Gmail probably the most famous example). This component needs a web server (for example, Nginx, Apache) and can be started directly on the mail server.

Examples: RoundCube and Citadel.

Mail Server Support

After reading the server components of the email you want to install and configure, consider the following question: why support a mail server can be too time-intensive and require high time? There are routine maintenance tasks: updating the rules of antivirus and spam filter, support for all components up to date, etc.; But in addition, there are many other points.

Black lists

One of the common problems belonging to the support of the mail server is the need to keep it outside of black lists (which are also called DNSBL, Blacklists, or Blackhole Lists). Such lists contain IP addresses of mail servers that distribute spam or "waste" mail, as well as servers with incorrectly configured DNS records. Many mail servers subscribe to one or even several such black lists, after which the incoming messages are filtered depending on whether the mail server is entered by sending a message to the list (or lists). If the mail server enters the emergencies, its outgoing messages will be filtered (and some are blocked) before sending to the recipient.

As a rule, the mail server that fell into emergency can be excluded from this list. To do this, you need to find out the cause of the server to the blacklist and eliminate it. Then you need to trace the process of deleting the server from the lists and subscribe at least one of them.

Troubleshooting

Although most people use e-mail every day, not every one can eliminate malfunctions in this complex system. For example, what if the sent messages were not accepted by the recipient? The problem may arise due to improper configuration of one of the many components of the mail server (for example, due to the poorly configured spam filter from outgoing messages, or external factors like black lists).

You can work with letters not only through the Yandex web interface, but also with the help of various mail programs installed on your computer.

Configure IMAP Program

When using the IMAP protocol, the mail program is synchronized with the server and saves the folder structure of your box. Letters you send via the postal program will be stored not only on the computer, but also on the server, and you can have access to them from various devices.

Before setting up the mail program, enable the IMAP protocol:

To configure the empt mail program, you must specify the following data:

Incoming mail

connection protection - SSL;

port - 993.

Outgoing mail

connection protection - SSL;

port - 465.

. rU »

The IMAP protocol support will turn on automatically when you first authorize in the postal program.

When using the POP3 protocol all letters from the folders that you specify in the menu Setting → Postal programswill be saved by the postal program on your computer into the incoming folder. If necessary, you can configure the filters in the mail program to automatically move the letters to the desired folders. You send letters will be stored only on your computer.

Note. When downloading letters from the server by the POP3 protocol Yandex.Mail automatically saves copies of letters on the server, but you can delete letters manually using the web interface. If you want to delete letters using a mail program, use the IMAP protocol.

Before setting up the mail program, enable the operation of the POP3 protocol:

To configure the POP3 mail program, you must specify the following data:

Incoming mail

connection protection - SSL;

port - 995.

Outgoing mail

email server address - smtp.yandex.ru;

connection protection - SSL;

port - 465.

To access the mail server, specify your login and password on Yandex (or if you have included two-factor authentication). If you configure the receipt of mail from the species box " [Email Protected]rU », the login is part of the address before the sign "@". If you use, you need to specify the full address of the mailbox as a login.

You can configure the receipt of letters through the POP3 protocol from any folder, including spam. To do this, open the menu Setting → Postal programs And check the desired folders.

When you download the contents of the box with mail programs, the default letters are not marked as read. If you want to march the received letters read, enable the appropriate option.

Problems with postal program

This step-by-step guide will help you solve problems associated with Yandex. The first and postal program.

This step-by-step guide will help you solve problems associated with mail in the composition of the Connect and the Postal Program.

Select Problem:

What message did you get?

Did you manage to log in?

So the problem was that you did not take the conditions. They are accepted automatically when you first log in in the Yandex.pox web interface.

Make sure the settings section includes the protocol you want to use.

Ensure that in the settings of the mail program you just specified \\ n The following server parameters: \\ N \\ N \\ n

If you are using imap

email server address - imap.yandex.ru;

connection protection - SSL;

port - 993.

email server address - smtp.yandex.ru;

connection protection - SSL;

port - 465.

\\ n \\ n \\ n \\ n \\ n

\\ N \\ n \\ n \\ n

If you use POP3

\\ N \\ N \\ n incoming mail \\ N \\ n

email server address - pop.yandex.ru;

connection protection - SSL;

port - 995.

\\ N \\ N \\ N \\ N Outgoing mail \\ N \\ n

email server address - smtp.yandex.ru;

connection protection - SSL;

port - 465.

\\ n \\ n \\ n \\ n \\ n

For details on how to check the configuration of servers in different mail \\ n programs, see section.

\\ n ")]))"\u003e

Make sure that you exactly indicate the following parameters of the servers in the mail settings:

If you are using imap

Incoming mail

email server address - imap.yandex.ru;

connection protection - SSL;

port - 993.

Outgoing mail

email server address - smtp.yandex.ru;

connection protection - SSL;

port - 465.

If you use POP3

Incoming mail

email server address - pop.yandex.ru;

connection protection - SSL;

port - 995.

Outgoing mail

email server address - smtp.yandex.ru;

connection protection - SSL;

port - 465.

For details on how to check the configuration of servers in different mail programs, see Encryption Transmitted Data.

If the message "Authentication Required" occurs, "Sender Address Rejected: Access Denied" or "Send Auth Command First", in the mailbox settings, authorization on the Yandex SMTP server is disabled. Make sure the option is enabled. User authentication (for Outlook Express) or SMTP authentication (For the Bat!).

If you are in the organization and the problem is played in all domain boxes, you need to log in to each of them in the web interface. Make it centrally will not work, because each mail user must accept the conditions independently.

If a message occurs "Sender Address Rejected: Not Owned by Auth User"The address from which you are trying to send a letter does not coincide with the login of which you are logged in on the SMTP server. Make sure that in the settings of the mail program as a return address specified exactly the address, the login from which is used in the authorization settings on SMTP.

If a message occurs "LOGIN FAILURE OR POP3 DISABLED"The mail program cannot access the POP3 mailbox. Make sure that the correct password from the box is entered and the POP3 protocol is enabled.

If a message occurs "Message Rejected Under Suspicion Of SPAM", the contents of your letter were recognized by Yandex. Good as spam. To solve the problem, open Yandex. Please send one any letter as a test. So you will prove the system that the letters sends not a robot.

Check your computer to viruses using free anti-virus programs: Cureit! From Dr.Web and Virus Removal Tool from Kaspersky Lab.

If you use an anti-virus program, a firewall or proxy server, disconnect them and check if the problem is reproduced.

Read step-by-step instructions for finding missing letters. Before starting work .

Select Problem:

When you delete the letters, they fall into the deleted folder and are stored in it 30 days. During this period, you can restore them:

Go to the deleted folder.

Highlight the desired letters.

Click the button to the folder.

If more than a month has passed since their removal, it will not be possible to restore the letters - they were forever deleted from Yandex.mount servers.

If there are no letters in the folder where they should be, then, most likely, they hit another folder, for example, to remote or spam. If you remember the name or sender address, part of the text of the letter or theme - try searching for letters in all folders of your box.

Letters found?

You can recover letters:

Go to the folder in which letters were found.

Highlight the desired letters.

Click the button to the folder.

Select the folder from the list where you want to move the letters - for example, incoming.

Why letters disappear and how to avoid

In a folder, the remote letters are stored 30 days, in the Spam folder - 10 days. After that, they will be forever removed from Yandex servers. Why letters can get into these folders without your knowledge:

Access to your mailbox has another user

Letters can be deleted by the user who has access to your mailbox: You may have forgotten to complete the session after working on someone else's device. To complete the session, click on the link Link menu Exit on all devices. Also this can be done on the page - by reference Exit on all computers.

Letters disappear in the postal program

Configure the program on the POP3 protocol

A rule is configured that removes or moves emails letters disappear in the postal program

If you use the postal program and remove letters in it, they disappear on it. This is because your program is configured by IMAP protocol - while the structure of the box on the service is synchronized with the box structure in the program. To delete letters only in the program, but leave it in Yandex. You can configure the program via POP3, but we recommend not to do this: letters may be incorrectly synchronized with the server.

The rule is configured that removes or moves letters Specify in Yandex. Specific and tie to the account. Perhaps our security system found your account suspicious and blocked the box. Most often, this is due to the fact that the phone number is not attached to the box or the fictional name and surname are indicated in the passport. A couple of hours usually goes to remove the lock.

If you delete the letters in the mail program, and on the Yandex. You are still in our folders, then, most likely your mail program is configured by the POP3 protocol. Due to the features of the POP3 protocol, letters in the mail program may incorrectly synchronize with the server. To work with Yandex. Please use the IMAP protocol. On how to reconfigure the mail program from POP3 to IMAP, see Transition from the POP3 protocol.

If sending sent letters are not displayed in the postal program, then, most likely, your mail program is configured by the POP3 protocol. Due to the features of the POP3 protocol, letters in the mail program may incorrectly synchronize with the server. To work with Yandex. Please use the IMAP protocol. On how to reconfigure the mail program from POP3 to IMAP, see Transition from the POP3 protocol.

If, when activating SSL encryption in the mail program, you get errors about an incorrect certificate, make sure that the mail program and the operating system are configured correctly:

Add a certificate to the list of trusted certificates manually (Windows)

Attention. If you are not sure that you can independently install the certificate, contact a specialist.

To add a certificate to a list of trusted certificates:

Download the certificate. (If the file exhibits the link right in the browser, click Ctrl + S. and save the file to the computer; Copy text from file No need.)

Open the Start menu.

In the search field, enter CERTMGR.MSC and press the ENTER key.

In the program window, in the folder tree, click on the folder Trusted root certification centers.

On the right side of the window, right-click on certificates and select All tasks → Import.

Today, when you can easily get any number of free mailboxes, simply by registering an account on the Yandex services, Male.ru and the like, such a question, as setting up the mail server, is not worried about many users.

However, there are such moments when you know at least some aspects of this issue will be useful.

When it happens

Situations where elementary knowledge on mail setting is needed by an ordinary user, not so much. Nevertheless, any of them can be involved in any way:

If it was decided to move from the browser to the selected program. After all, in many ways, such clients are preferable: they allow you to combine the mail program with an organizer, a notebook, and more flexibly manage the address book and administer messages.
There was an unexpected failure in the work client, "flew" all settings. And then you just need to install the mail server. Its setting usually does not require much time and strength, but otherwise you can stay without mail for quite a long time.
Free mailboxes can be destroyed by the administration, and without explaining the reasons. Yes, and looks like such a box in the eyes of business partners, just say, no one. And therefore will have to start the selected, on the server.
If the provider offers a separate mailbox, then why not take advantage of this offer.

Configuring Windows Mail Server

The main email parameters, such as DNS, IP data and similar information are displayed directly by the provider.

To start using Windows, you will need to either download a customer suitable for this operating system, or resort to assistance to the customers built into it. To begin with, you will need to make a new account. As a rule, it is also asked to enter its name, come up with a password and login to enter.

It may be necessary to enable support for Windows email services via the "Delete and Installation Program" panel in the Installation section of the E-Mail Services components.

To create a new box, you will need to come up with a username and password.

In SMTP, you need to specify the port number 25, and for the server POP3 - 110. If the provider displays other parameters, you should enter them. In the case when the mail client does not assume to enter the port number, you need to leave only the address issued by the provider, in the "Server for Incoming Messages" (this can be both POP3 and IMAP) and "Name for Outbound Server" ( Usually only SMTP).

A more subtle configuration of Windows Mail Server largely depends on the mail application used, but the principle of operation will be the same. The difference can be in the graphical interface versions and in the menu items.

Transition from free mail to the selected client

Sometimes it is necessary to stay on free however, to apply a separate application as a client. You can show this on the example of mail settings for the Yandex service. Setting the mail server will then be carried out with the following parameters.

1. Settings on the IMAP protocol for incoming messages:

mail Server Address: imap.yandex.ru;
in the defense protection parameters, SSL should be specified;
the port number is indicated 993.

2. For outgoing messages on the IMAP protocol:

as an address address, specify SMTP.yandex.ru;
in the connection protection options, you also need to set SSL;
the port number must be set 465.

3. With regard to the POP3 protocol for sent messages:

as an address of the server, specify pop.yandex.ru;
sSL is indicated as the protection parameters of the connection used;
the port number is indicated 995.

4. For outgoing messages sent by the POP3 protocol:

as an address of the mail server, SMTP.yandex.ru is specified;
in the protection parameters for the connection used, it is indicated again SSL;
port number is exhibited 465.

As a username, as well as addresses and passwords, you should set existing addresses and passwords from the mail to Yandex.

Setting up the Mail.ru server.

Sometimes you need to learn about the settings of Mail.Ru Mail Server. In general, the setting looks in the same way as described in the case of Yandex mail. But the parameters will look like this:

full email address (in the format with the @ icon, for example [Email Protected]);
the imap server is indicated by imap.mail.ru;
for the SMTP server specifies smtp.mail.ru;
the username is the full email address from the already existing mail;
password is a password used by mail;
IMAP: number 993 (for SSL / TLS protocols);
POP3: number 995 (for SSL / TLS protocols);
SMTP: number 465 (for SSL / TLS protocols);
you need to specify that you want to authorize the server sent letters, in the authentication parameters - a simple password, without encryption.

In general, the settings are indicated exactly the same as in the case of "Yandex", but only with the addition of the Mail prefix. For other free servers, you should set the same parameters, but with the corresponding prefixes.

As can be seen, in general, nothing complicated in this question as the mail server setting is not. Even a novice user can cope with this task. But you can confident that even in the case of a critical failure without mail, it is not necessary.

The task is to raise your own email servers using Linux tools, Apache, SQL and the like requires deeper knowledge in the field of information technology.

Email - a service that allows you to exchange through a computer network by emails.

The main feature of the email is that the information is sent to the recipient not directly, but through an intermediate link - an email box, which is a place on the server, where the message is stored until the recipient requests it.

Mail Server is a computer program.intended for the organization of email exchange between computers. Its main features are reception of letters from customers and delivery to their addressees. The clients can act as users (by the Email Client Program) and other mail servers.

Users using the Mail Client program (Outlook Express, Thunderbird, etc.) can create letters, send them to the server and take mail from their mailboxes on the server.

Communicating the server and client occurs on special mail protocols - Simple Mail Transfer Protocol (SMTP) - when sending letters to the server and POST Office Protocol v.3 (POP3) - when receiving letters from the mailbox. Customer connection to the server occurs through certain ports. For SMTP, the standard is port 25, for POP3 - port 110.

There are various mail servers. As an example, consider the installation and configuration of the mail server Courier Mail Server.

Courier Mail Server is an email server (email server) for Windows for local networks. It will help you quickly organize email exchange on the local network and on the Internet. Courier Mail Server does not require installation in the system. It is enough to download the archive with the program and unpack it into any folder on the hard disk of the computer, which will work as a mail server.

You can download the free version of Courier Mail Server 1.56 from http://courierms.narod.ru/. A more functional Courier Mail Server 2.05, but the already paid version (1650 rubles per 10 mailboxes, the restriction of the demo version - only 3 mailboxes), can be found on the site http://www.courierms.ru/.

In this example, we will customize and use the free version of the Courier Mail Server 1.56 email server.

Advantages of Courier Mail Server 1.56:

free
easy installation and removal
compactity
easy administration
small system resource consumption
multiple thread
comfortable graphic shell
russian-language interface and documentation
support for an unlimited number of mailboxes

The program is running Windows 9X / ME / NT / 2000 / XP. The program setting is quite simple and is available to the usual user.

Note: In the example, all network computers run running Windows XP. All computers in the network are the same (there are no dedicated computers servers). The teacher's computer has server name, PC01, PC02 pupil computers, etc. All software, considered in this section, is placed in the folder C: \\ MyServers \\ usr \\ Local \\. If your computers have other names (and it is most likely :)), then consider it when setting up software. Also you can choose and to a friend folder to install the program.

CMS comes in the form of a zip archive containing executable file and documentation. To install the server, create a folder in which it will operate, remove files from the archive to this folder and run the application Courierms.exe..

When you first start the server, the server inside its folder will automatically create the subfolders and files necessary for its operation. Outside its folder, the server does not produce any changes. The Windows registry changes only when registering as a service.

Courier Mail Server can be launched as a standard application, as well as as a Windows service. To start as Windows, start the CMS and in the Setup menu, click Start Service. At the same time, the Courier Mail Server service is registered in the system.

If the launch occurred normally, the main server window appears on the screen, and in the system tray (System Tray) next to the clock - its icon .

If the main window appeared messages about the start of SMTP and POP3 servers and there are no error messages, you can proceed to configure the server.

The next step of setting up the mail server is reduced to the input of local domains. To do this, double-click on the word "domain" and the tab will open to configure it. Enter computer namewhere the mail server will work. In our example, this is Server.If you have a computer name, for example, PC11, then enter this name.

Any server program implies the input of users who will be serviced by it. Make a double click on "Accounts" and the account editor opens. Account editor is designed to maintain a list of local users (account) server. When creating an account, it is created, also, the corresponding mailbox folder. When you delete an account, the mailbox folder is automatically deleted with all content. When you first start the server, the PostMaster account is automatically created. .

Create the required number of accounts for your users. It is enough to create a student and teacher one on each computer, although you can create a hotel account and each student.

Each account has the following parameters:

Real name: The name of the owner of the mailbox.

Mailbox name: Name of mailbox. It is also a username when connecting to the server. In the box name, do not use Russian letters and special characters, because Some postal programs work incorrectly with them. If the name of the box pC 01., Local domain server , then the email address of this user pC. [Email Protected] server.

Password: Password for connecting to the server.

Other parameters we will not change.

We have 11 computers in class (along with teacher) so we have created 11 accounts.

Limit access to the mail server can be using an IP filter. Specify the range of IP addresses to which is allowed. We have 192.168.1.1-192.168.1.11 (read about the IP addresses and their setting in other articles of this). At your school, this range can be different, for example, the one that issued you the Internet provider (well, this is another article).

Everything! The mail server can be used. You can read about the configuration and use of other features of the program in the reference (in Russian!).

You ask: "How to use it? How to send and receive letters?". The answer is simple. Letters we will send and receive using the Mail Client program (Outlook Express, Thunderbird, etc.). And about how to do this in the next article: "".