Select the ‘Accounts Settings’ from the Thunderbird Menu->Options.
Click on the Outgoing Server (SMTP). Select your current SMTP server and click ‘Edit…’. If you have no SMTP server set up yet, click ‘Add…’.
Change the Server Name setting to mail.smtp2go.com. Change the Port setting to 2525. You can also try using Port 25, 8025 or 587.
Set Connection security to ‘STARTTLS’ and Authentication method to ‘Encrypted password’.
Enter your SMTP Username into User Name.
If you wish to use a non-secure connection, set Connection security to ‘None’ and Authentication method to either ‘Password, transmitted insecurely’ or ‘Encrypted password’.
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