Thunderbird Setup Guide

Mozilla Thunderbird · Windows / Mac / Linux

Mozilla Thunderbird is a free, open-source email client available for Windows, Mac, and Linux. These steps work on all current versions of Thunderbird.

Settings at a Glance

Incoming Mail (IMAP)

Server imap.topmail.com
Port 993
Security SSL / TLS
Authentication Normal password
Username your email address

Outgoing Mail (SMTP)

Server smtp.topmail.com
Port 587
Security STARTTLS
Authentication Normal password
Username your email address

Steps

1

Open the account setup dialog

Open Thunderbird. If the account setup wizard doesn't appear automatically:

  • Click the ≡ (hamburger menu) at the top-right → New Account → Existing Mail Account…
  • Or: click File in the menu bar → New → Existing Mail Account…
Thunderbird initial setup screen
The Thunderbird account setup screen
2

Enter your account details

Fill in the three fields:

  • Your full name: your name (shown on outgoing emails)
  • Email address: your full email address
  • Password: your email password

Click Continue. Thunderbird will attempt to find settings automatically. Once the lookup fails or times out, click Configure Manually.

Account details form in Thunderbird
Enter your name, email, and password, then click Configure Manually
3

Enter incoming (IMAP) settings

The manual configuration panel shows INCOMING SERVER and OUTGOING SERVER sections on the same screen. Fill in the Incoming Server fields:

  • Protocol: IMAP
  • Hostname: imap.topmail.com
  • Port: 993
  • Connection security: SSL/TLS
  • Authentication method: Normal password
  • Username: your full email address
Thunderbird manual configuration panel showing incoming and outgoing server fields
The manual config panel — set INCOMING SERVER as listed above, then scroll to OUTGOING SERVER for Step 4
4

Enter outgoing (SMTP) settings

On the same panel, scroll down to the Outgoing Server section and fill in:

  • Hostname: smtp.topmail.com
  • Port: 587
  • Connection security: STARTTLS
  • Authentication method: Normal password
  • Username: your full email address
Check the port. Thunderbird may pre-fill port 465 with SSL/TLS for outgoing — change it to 587 and connection security to STARTTLS as shown in the values above.
5

Test and confirm

Click Re-test. Thunderbird will attempt to connect to both servers using the settings you entered. If the test succeeds, you'll see a green confirmation message.

Click Done to finish. Your Topmail account will appear in Thunderbird's left-hand sidebar.

Test fails? The most common cause is a typo in the server name or using the wrong port. Double-check the values above and run Re-test again.

Troubleshooting

Re-test fails for incoming server

Confirm the IMAP server is exactly imap.topmail.com, port 993, connection security SSL/TLS, authentication Normal password, and the username is your full email address.

Re-test fails for outgoing server

Confirm the SMTP server is smtp.topmail.com, port 587, connection security STARTTLS. Make sure authentication is Normal password and the username field is filled in.

Thunderbird prompts for a password repeatedly

Open Thunderbird's Password Manager (Tools → Password Manager), remove any saved entry for topmail.com, and restart Thunderbird to re-enter the correct password.

Emails are not downloading

Right-click your account in the sidebar and choose Get Messages, or check Tools → Account Settings → Server Settings and ensure the folder polling interval is set appropriately.

Still having trouble? Our team is happy to help. Call +44 117 463 3403 or email support@topmail.com.