The MBK Laboratory develops the Tegu mail server, which combines the functions of an SMTP and IMAP server. A web interface is provided to simplify the management of settings, users, storages, and queues. The server is written in Go and distributed under the GPLv3 license. Ready-made binary assemblies and advanced versions (authentication via LDAP/Active Directory, XMPP messenger, CalDav, CardDav, centralized storage in PostgresSQL, failover clusters, a set of web clients) are supplied commercially.
Key features:
- Native server implementation for SMTP and IMAP protocols.
- Delivery of messages to a third-party server using the LMTP protocol (for example, Dovecot) or to your own maildir storage.
- WEB administration panel.
- Local database of users, groups, redirects.
- Support for mailbox aliases, forwarding lists (mailing lists), mail groups (groups with an email address allow you to deliver a letter to all their members), mail group nesting
- Content of an unlimited number of mail domains. One or more databases of users and groups can be connected for each domain.
- Master mail users (those who have access to all mailboxes) are defined by group membership.
- Support for setting quotas on IMAP mailbox sizes.
- Support for white and black lists of senders for incoming emails.
- SPF support for sender domain verification.
- Support for GreyList technology (temporary refusal to an unknown sender).
- DNSBL support (allows you to deny service to senders based on databases of compromised addresses).
- Ability to check for viruses and spam using the Milter protocol to access external anti-virus and anti-spam systems.
- Adding a DKIM signature for outgoing messages.
- Password protection with IP ban (SMTP, IMAP, WEB).
- Modular architecture for user and group databases, mail storages, message queue handler.
- The project is registered in the register of domestic software of the Ministry of Digital Development of Russia.
Source: opennet.ru