25 | smtp | Postfix | Used for communication betweem mail servers. __WARNING__: This port __MUST__ be open, otherwise you cannot receive email sent by other mail servers. | __YES (REQUIRED)__{: .red }
110 | pop3 | Dovecot | Used by end users to retrieve emails via POP3 protocol, secure connection over STARTTLS is enforced by default. | YES (open to your end users)
995 | pop3s | Dovecot | Used by end users to retrieve emails via POP3 protocol over SSL. | YES (open to your end users)
143 | imap |Dovecot | Used by end users to retrieve emails via IMAP protocol, secure connection over STARTTLS is enforced by default. | YES (open to your end users)
993 | imaps | Dovecot | Used by end users to retrieve emails via IMAP protocol over SSL. | YES (open to your end users)
4190 | managesieve | Dovecot | Sieve service used by end users to manage mail filters. Note: in old iRedMail releases, it's port 2000 (deprecated and not even listed in `/etc/services` file). | NO (disabled by default and users are forced to manage mail filters with webmail)
10024 | | Amavisd-new | Used to scan inbound messages, includes spam/virus scanning, DKIM verification, applying spam policy. | NO (listen on `127.0.0.1` by default)
10026 | | Amavisd-new | Used to scan outbound messages, includes spam/virus scanning, DKIM signing, applying spam policy. | NO (listen on `127.0.0.1` by default)
10027 | | Amavisd-new | Used by mlmmj mailing list manager, it bypasses spam/virus/header/banned checks by default, but have DKIM signing enabled. | NO (listen on `127.0.0.1` by default)
10028 | | Postfix | Used by Amavisd-new to handle email message sent by mlmmj mailing list manager. Introduced in iRedMail-0.9.9. | NO (listen on `127.0.0.1` by default)
7790 | http | mlmmjadmin | RESTful API server used to manage mlmmj mailing lists. Introduced in iRedMail-0.9.8. | NO (listen on `127.0.0.1` by default)
7791 | http | iredadmin | iRedAdmin (standalone uwsgi instance). Introduced in iRedMail-0.9.9. | NO (listen on `127.0.0.1` by default)
11211 | | Memcached | A distributed, high performance memory object caching system. Currently used by only SOGo Groupware. | NO (listen on `127.0.0.1` by default)