Incoming (receiving) email protocols:

• POP3:
  • Unencrypted Port: 110
  • Encrypted/Secure Port: 995
  • Encryption Type: SSL or TLS
• IMAP:
  • Unencrypted Port: 143
  • Encrypted/Secure Port: 993
  • Encryption Type: SSL or TLS

Outgoing (sending) email protocols:

• SMTP:
  • Unencrypted Port: 25
  • Encrypted/Secure Port: 587
  • Encryption Type: STARTTLS
• SMTPS:
  • Unencrypted Port: N/A
  • Encrypted/Secure Port: 465
  • Encryption Type: SSL or TLS

Note that for SMTPS, there is no unencrypted port available, as it always uses encryption to secure the connection. Also, STARTTLS is a protocol that allows an existing unencrypted connection to be upgraded to an encrypted one during the email transmission process.