IMAP & SMTP Settings for All Clients

The easiest option is Apps & devices, which gives you guided steps and the exact server names for the selected mailbox. Use the reference below when an app asks you to enter the details manually.

Who this is for

• Users configuring a desktop or mobile email client.
• Developers configuring a script to send email.

1. Incoming Mail (IMAP)

Use these settings to receive email.

Note: TrekMail does not support POP3. Use IMAP to keep folders and message state synchronized across devices.

2. Outgoing Mail (SMTP)

Use these settings to send email.

A verified White Label setup can show branded IMAP and SMTP hosts. Use those values when they appear; do not replace them with a hostname guessed from the mailbox address. Port 587 with STARTTLS is the supported SMTP alternative when port 465 is blocked.

IMAP Connection Limits

To ensure fair resource usage and server stability, TrekMail enforces concurrent IMAP connection limits based on your subscription plan.

• Per IP: Maximum simultaneous connections from a single IP address (e.g., your home network).
• Total: Maximum simultaneous connections across all devices and locations.

What happens if I exceed the limit?

Your email client will receive a "Maximum connections exceeded" error and won't be able to establish new IMAP connections until existing ones are closed.

Tips to avoid connection limits

• Close unused email clients: If you have multiple devices, close email apps you're not actively using.
• Check client settings: Some email clients open excessive connections. Configure them to use fewer simultaneous connections.
• Upgrade if needed: If you regularly hit the limit with normal usage, consider upgrading to a higher plan.

CalDAV / CardDAV (calendar and contacts)

In addition to IMAP/SMTP for mail, TrekMail exposes calendar and contacts over CalDAV/CardDAV. This is what your phone or desktop calendar app uses to sync events and contacts.

For platform-specific guides see: Apple · iPhone/iPad · Android · Thunderbird · Outlook (caveats).

Important Notes

• Username: Always use the full email address. Just alice will fail.
• Passwords: Use the specific mailbox password you set when creating the user, not your TrekMail account password.
• App Passwords: We do not require specific "App Passwords". Use your standard mailbox password.
• Custom SMTP routing: If your plan does not include managed sending, configure your provider under the domain's SMTP settings first. Your email app still connects to the outgoing TrekMail or branded host shown in Apps & devices with the mailbox password. TrekMail applies the private provider route behind the scenes; do not place the provider's secret credentials in an end user's email app.