You can integrate your Mailfence account into Thunderbird using SMTP and IMAP/POP. This feature is available in paid plans.
- Open your Thunderbird client.
- Go to File -> New -> Existing Mail Account.
- Enter your Mailfence account Display name, Email address and Password.
- Keep Remember password checked (optional).
- Select IMAP or POP3.
- Click on Done.
All of the respective configuration settings for SMTP, IMAP and POP for your Mailfence account can be found in your account Settings -> Account -> My connection settings.