AfterLogic MailSuite Pro for Linux - 7.7.5
The complete mail server built upon industry-standard components and bundled with the modern, fast and clean webmail, personal calendar, and address book.
The webmail supports skins, mobile layout for smartphones, lets users access and manage mail folders, browse emails using preview pane and compose new ones with rich-text editor, drag-n-drop attachments from and into the browser, open zip and winmail.dat attachments, preview images and PDF files, have contacts and groups in address book, use identities, filters, and also check POP3/IMAP accounts on external mail servers.
The calendar lets users schedule events with reminders and export calendars as iCal files. For mobile sync, the calendar acts as CalDAV server. Address book works as CardDAV server, respectively.
Thanks to iOS profiles support, iPhone and iPad users can have their IMAP/CalDAV/CardDAV settings be delivered automatically on their devices.
Interface is localized for many languages, supports right-to-left rending for Arabic and Hebrew, different date and time formats, timezones, email reader supports UTF-8 and most other encodings.
With the web administration panel, the admin can quickly create or manipulate domains, users and server settings.
MailSuite Pro fully supports desktop and mobile mail clients and implements POP3, IMAP, SMTP protocols (including SSL/TLS and SMTP authentication).
Other features include: unlimited domains, aliases, spam protection (SpamAssassin), antivirus (ClamAV), mailing lists, logging, Sieve filters, forwarding, change account password by the user.
The web part (webmail and admin panel) is written in PHP and comes with the source code which can be modified for your needs. Rich plugin and integration API.
Database backend is MySQL. The mail server core is Exim (SMTP) and Dovecot (POP3/IMAP). Built-in web server is Nginx (you can switch the web part to your Apache if desired). Available as 64-bit RPM and 64-bit VMWare image (based on CentOS 7).