Technologies: GNU/Linux,Postfix,Courier IMAP,Fetchmail
A mail server is a program,and by extension the computer that runs it,that takes care of sorting the e-mails from one computer to another.
Our choice is Postfix,which includes among its merits the enormous tolerance and ability to control the buffer overflow and its capability of handling large amounts of e-mails.
Postfix is structured in different services each playing a single function and running with minimum rights.
This ensures that any bugs or exploits involving a part of Postfix does not compromise the whole e-mail delivery system.
It offers support for mailbox,maildir,virtual domains and also allows manipulation of addresses,SASL authentication and many more.
- IMAP and POP3 e-mail boxes
Courier-IMAP server,an IMAP server fast and scalable that supports the boxes in maildir format. This is the same IMAP server included in the broader project Courier,allows you to read your mail keeping it on the server,without the need to download it.
- Authenticated SMTP
One of the limitations of the original SMTP protocol is its incapacity managing the authentication of senders. In addition to the risk of spam,it’s possible to send an e-mail with the sender appearing as the address corresponding to another account. To overcome these problems our configuration uses SMTP-AUTH:a module that handles authentication of the sender.
- Antispam check
Our e-mail spam filtering choice is SpamAssassin. It is based on context compare rules,also supports rules based on DNS,checksum and filtering statistics. SpamAssassin is considered one of the most effective antispam filters,especially when used in conjunction with a spam database.
- Antivirus check
Clam Antivirus is born primarily for integration with the MTA (particularly the scanning of attachments). The module provides a flexible and scalable service,a scanner command line and a tool for the automatic update from the Internet. Note that the virus database is kept constantly updated (it’s updated several times a day).
- E-mail download from other accounts
Fetchmail is a program that deals with receiving mail from your remote email boxes,such as that provided by your ISP.