Setting up Thunderbird with IMAP and SMTP
This guide sets up Mozilla Thunderbird against an ITProMail mailbox using IMAP for incoming mail and authenticated SMTP for outgoing mail. It also covers enabling Thunderbird's built-in OpenPGP support. Mail clients do not use your account password. They use an app password, which you create in the webmail and can revoke without changing your login.
Step 1: Create an app password
Sign in to the webmail, open Account, then Security, and create a new app password. Give it a label that names the client, such as "Thunderbird laptop", so you can revoke it later without affecting other devices. Copy the generated password and store it in a password manager before you close the dialog.
Step 2: Add the account manually
Open Thunderbird and choose the option to add a mail account. Enter your name, your full email address and the app password, then continue. If Thunderbird does not find settings automatically, choose manual configuration and enter the values below.
| Setting | Value |
|---|---|
| Incoming protocol | IMAP |
| Incoming server | imap.itpromail.com, port 993 |
| Incoming connection security | SSL/TLS |
| Incoming authentication | Normal password |
| Outgoing server | smtp.itpromail.com, port 465, SSL/TLS |
| Outgoing authentication | Normal password |
| Username (both servers) | Your full email address |
If your network blocks port 465, use smtp.itpromail.com on port 587 with STARTTLS instead. Do not turn off encryption for either server.
Thunderbird will check the server certificates. Confirm that the host name shown matches imap.itpromail.com or smtp.itpromail.com exactly. Accept the certificate only when the names match.
Step 3: Verify
After the account is created, Thunderbird should list your folders and download the Inbox. Send a test message to an address you control, then check that it arrives in the Sent folder on both the client and the webmail. Thunderbird keeps one IMAP connection per folder it is actively syncing, so a large first sync can take a while.
Step 4: Enable OpenPGP
Current Thunderbird releases include OpenPGP support without an add-on. Open the account settings for the mailbox, choose End-to-End Encryption, and add a key. You can generate a new key or import one you already use. Keys you manage here are also visible in Thunderbird's OpenPGP Key Manager, which is the place to export a public key or create a revocation certificate.
Once you have a key, export the public part and publish it through the account's PGP settings, which are under Account, then Encryption in the webmail. Publishing the key through the Web Key Directory lets other OpenPGP clients find it from your address. The full process is described in PGP in ITProMail.
Keep a copy of your private key and its revocation certificate somewhere offline. A key that is lost cannot be recovered from the server.
Troubleshooting
If login fails, confirm that you used the app password and not the account password, and that the username is the full address. If folders do not sync, check that the incoming server is set to SSL/TLS on port 993. For more, see troubleshooting login.