Why use your own mail server instead of using the one at your service provider? There are a number of reasons:
- Control. When you run your own mail server, you can change service providers, add a redundant internet connection, schedule your own backups, manage your own mail-lists, and supervise your user accounts.
- Flexibility. You can easily configure additional temporary email accounts, or an additional domain name for a trial venture or special product, or have open or moderated mail lists.
- Alternatives. Using your own email server, all mail can be retained on the server instead of on individual computers. Using this option, travellers or employees working from home will have the exact same mailbox contents on their laptop, home, and office machines.
- Reliability. You can run backups on a schedule that works for your needs, including automatic mirroring of all mailboxes to a second machine (perhaps located offsite) to ensure disaster recovery.
- Security. An attack on your service providers' mail servers will not impact your machines. Many service providers use the industry standard "sendmail" application, which has a long history of security compromises and exploits. Your own mail server will run "qmail", which has had a cash reward available since March of 1997 for anyone who can find a verifiable security hole in it. No one has yet been able to find a hole, even though the source code is publicly available.
CoSysCo provides mail servers built and configured to your needs based on the most secure mail transfer agent (MTA) available, qmail. Your mail server can be set up to handle any number of domains, with any number of users per domain. Access to the mail server is via web browsers, POP3, IMAP, IMAP-SSL, and SMTP protocols. Simple mail-list management is provided, and almost all administration can be done via web browser interfaces. A variety of anti-spam techniques are available, if desired. Since any spam filtering is a tradeoff between false negatives and false positives, your system can be configured according to your desired strength of filtering. The use of multiple virtual accounts with the ability to drop known spam targets can greatly reduce the incidence of spam. Mail volume handled by the server can be small to very large.