Our email services support auto-discovery and most email clients will automatically configure themselves to the optimal settings available. When manual setup or troubleshooting is required, our email servers support connections over specific ports for SMTP, POP3, and IMAP. The recommended settings are the encrypted options: SMTP on port 465 (SSL/TLS), IMAP on port 993 (SSL/TLS), and POP3 on port 995 (SSL/TLS).

Selecting the right port and security type is essential for successful authentication and data protection. Encrypted connections prevent credential theft and message interception on untrusted networks. Our servers also provide alternate ports to work around common ISP restrictions.

#Supported Ports

The complete list of ports our mail servers accept is shown below. Recommended settings are indicated in bold.

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Protocol | Security Type | Port Number(s)
--- | --- | ---
SMTP | Encrypted (SSL or TLS) | **465**
SMTP | Encrypted (STARTTLS) | 587 or 25, 26, 2025, 2525
SMTP | Unencrypted | 25, 26, 2025, 2525
IMAP | Encrypted (SSL or TLS) | **993**
IMAP | Encrypted (STARTTLS) | 143
IMAP | Unencrypted | 143
POP3 | Encrypted (SSL or TLS) | **995**
POP3 | Encrypted (STARTTLS) | 995
POP3 | Unencrypted | 110

Most ISPs block port 25, so we recommend using an alternate port if you need to use unencrypted or STARTTLS connections. Port 587 is the standard submission port for authenticated SMTP with STARTTLS.

#Protocol Fundamentals

SMTP (Simple Mail Transfer Protocol) handles outgoing mail submission from your client to the server and server-to-server delivery. IMAP (Internet Message Access Protocol) lets you read and organize mail while keeping it synchronized on the server across multiple devices. POP3 (Post Office Protocol v3) downloads messages to a local client and, by default, removes them from the server.

Ports differ by security mode. Ports 465, 993, and 995 expect an encrypted connection immediately (implicit TLS). Ports 25, 110, and 143 start unencrypted and can upgrade via STARTTLS if both sides support it. Always match the port to the chosen security type in your client.

#Manual Configuration Steps

Prerequisites include your full email address, password, and mail server hostname (typically mail.yourdomain.com). Use the recommended encrypted ports above. Enable authentication on the SMTP server with the same credentials used for incoming mail. Avoid mixing a STARTTLS port with an SSL/TLS setting or vice versa.

#Example Secure Settings

Incoming Server
  Protocol: IMAP
  Hostname: mail.example.com
  Port: 993
  Security: SSL/TLS
  Username: user@example.com

Outgoing Server
  Protocol: SMTP
  Hostname: mail.example.com
  Port: 465
  Security: SSL/TLS
  Authentication: Enabled
  Username: user@example.com

#Common Pitfalls and Troubleshooting

  • ISP blocking port 25: Switch to 587 (STARTTLS) or 465 (SSL/TLS). Test each alternate port in sequence.
  • Connection timeouts or refused errors: Confirm the port matches the security setting and that no local firewall is interfering.
  • Authentication failures: Use the full email address as the username. Disable any "secure password authentication" (SPA) options unless required.
  • Certificate errors: Verify the hostname entered exactly matches the certificate presented by the server.

Prioritize the recommended encrypted ports for both security and compatibility. Auto-discovery will select these settings for most clients when DNS records are configured correctly. For client-specific instructions, consult our knowledge-base articles covering Outlook, Thunderbird, and mobile device setup.