Mailserver Port Numbers
Following are port numbers for different services:
- SMTP – 25 (465 with SSL, 587 with TLS)
- POP3 – 110 (995 for SSL)
- IMAP – 143 (993 for SSL)
- ManageSieve – 4190 (Gmail-like mail filtering)
- Amavis – 10025 (spam/antivirus checks)
You can find/verify ports used by postfix and dovecot using following commands:
netstat -tulpn | egrep 'master|dovecot'