Mail. Connecting a mailbox to Thunderbird

A mailbox created with BeAdmin can be connected to Thunderbird over IMAP and SMTP; Thunderbird runs on Windows, macOS, and Linux. This article is a continuation of Mail. Connecting a mailbox to a mail client: it does not repeat the common server settings or the answers to typical problems, only the steps in Thunderbird. The table of server settings is in the Server settings section.

What you need

You will need the mailbox address and password and the mail server address, for example mail.example.com. The password is shown only once, in the "Mailbox created" dialog, so you need to save it when you create the mailbox; if you did not, change the password. You can open the server address and the login at any time in the expanded mailbox — see Where to find the settings.

Adding the mailbox

1. In Thunderbird, open the app menu and choose "Add Account", then "Email". If you are starting Thunderbird for the first time, the account window opens on its own.
2. In the "Full name" field, enter the name your recipients will see. In the "Email address" field, enter the mailbox address, for example info@example.com. Click "Continue".
3. Thunderbird tries to detect the server settings itself. If it finds them, check that:
   • for incoming mail — IMAP, your mail server address, port 993, SSL/TLS;
   • for outgoing mail — the same address, port 465, and SSL/TLS. Port 587 with STARTTLS works as well.
4. If the settings it found match these, make sure IMAP is selected and click "Continue". IMAP keeps messages on the server, so the mailbox looks the same in Thunderbird and on your other devices. If they do not, click "Edit configuration" and enter the values as described in Manual setup.
5. Enter the mailbox password and click "Continue".
6. If Thunderbird offers to connect address books and calendars, click "Skip". When a message says the account has been added, click "Finish".

Manual setup

If Thunderbird does not find the settings, it reports that it failed to find the settings for your email account. Click the "Manual configuration" link and fill in the server settings.

Incoming mail server:

• "Protocol" — IMAP.
• "Hostname" — the mail server address, for example mail.example.com.
• "Port" — 993.
• "Connection security" — SSL/TLS.
• "Authentication method" — "Normal password".
• "Username" — the full mailbox address, for example info@example.com.

Outgoing mail server:

• "Hostname" — the same mail server address.
• "Port" — 465.
• "Connection security" — SSL/TLS.
• "Authentication method" — "Normal password".
• "Username" — the same mailbox address. If there is a "Same username as incoming server" checkbox, select it.

Thunderbird tests the connection and asks for the mailbox password. Enter it and finish with the "Finish" button.

Checking that it works

Send a message to the same mailbox: this checks both directions at once. It should go out without errors and appear in the "Inbox" folder — that means both outgoing (SMTP) and incoming (IMAP) mail work.

If Thunderbird warns about the certificate

If Thunderbird reports an unverified certificate and offers to add a security exception, do not add one: otherwise your password and messages would go to a server whose identity Thunderbird has not verified. First check that the "Hostname" field contains the mail server address, not the primary domain or an IP address. For other causes and how to fix them, see If the mail client warns about the certificate.

What's next

• Mail. Connecting a mailbox to a mail client — server settings and what to do if the mail client does not connect.
• Mail. Mailboxes, aliases, and domains — creating a mailbox and changing its password.