iRedMail is a full-featured mail server solution, it provides basic features like unlimited virtual mail accounts, POP3/IMAP/SMTP, AJAX webmail. Below are some highlights we think you might be interested in.

Works on 9 Major Linux/BSD Distributions

Distribution Version (the releases marked in red are recommended) i386 x86_64
Red Hat Enterprise Linux CentOS Scientific Linux Scientific Linux 5.x, 6.x
Debian 6.x (Squeeze), 7 (Wheezy)
Ubuntu 12.04 LTS (precise), 13.04 (raring)
Gentoo Linux Gentoo Linux The latest release (or daily build) with the latest portage
openSuSE 12.2, 12.3
FreeBSD 9.x
OpenBSD 5.2, 5.3

Fast Deployment, Low Maintenance, Unlimited Accounts

  • Deploy full-featured mail server in LESS THAN 1 MINUTE, low maintenance after deployed. (View YouTube Video to check how easy it is)
  • Unlimited number of virtual mail domains, users, mail lists, aliases, admins.

Stores Virtual Mail Accounts in OpenLDAP, MySQL or PostgreSQL

Backend Web-based Admin Tool Built-in Mail List Built-in Global LDAP Address Book
OpenLDAP iRedAdmin, phpLDAPadmin
MySQL iRedAdmin, phpMyAdmin
PostgreSQL * iRedAdmin, phpPgAdmin
Note: PostgreSQL support is available on RHEL/CentOS (6.x), Debian 7 (Wheezy), Ubuntu (12.04 and later releases), FreeBSD, OpenBSD.

Service Restrictions

Service Per-user support Per-domain support
Mail service
Monitor incoming/outgoing mails with BCC
Sending mail via SMTP, fetching mail via POP3/IMAP
Sending mail vai SMTPS (SMTP over TLS/SSL), fetching mail via POP3S/IMAPS
Receiving mail
Mail forwarding
Customize mail filter rule
Note: Mail service means all mail related services, include POP3, IMAP, SMTP and other services listed above.

Sender & Recipient Throttling

  • Max message size of single outgoing email
  • Max message size of all outgoing emails per time unit
  • Number of max outgoing emails per time unit
  • Number of max incoming emails per time unit

Note: You can manage throttling with phpMyAdmin or iRedAdmin-Pro admin panel.

Anti-Spam & Anti-Virus

  • Quarantining SPAMs into MySQL database, release or delete them with iRedAdmin-Pro.
  • SPF (Sender Policy Framework) Validation support.
  • DKIM (DomainKeys Identified Mail) signing and verification support.
  • Greylisting support.
  • Whitelist support. Based on IP address, sender address, DNS name.
  • Blacklist support. Based on IP address, sender address, DNS name, HELO.
  • HELO Randomization Prevention (HRP) support.
  • Spamtrap support.
  • SpamAssassin integration.
  • ClamAV integration for anti-virus, auto-update virus database.

WebMail: AJAX, Global LDAP Address Book, Vacation, Filter

WebMail Global LDAP Address Book Support Vacation Support Mail filter Support
Roundcube WebMail

Misc

  • All components are free, open source. You can always get software update from official Linux/BSD repositories.
  • Mail deliver restriction of mail list/alias account.
  • Catch-all account support.
  • Shared mailboxes.
  • Force user to change password in 90 days.
  • Backup MX support.
  • Log basic info of all incoming and outgoing emails.
  • Store realtime quota usage in MySQL. You can easily view them in your own admin panel.

Main components and working process

Image comes from: http://workaround.org/ispmail/lenny/bigpicture