Whether you may be troubleshooting your email client or setting it up for the first time, these instructions will walk you through an important part of making sure you are successfully sending email with Thunderbird®:

  1. 1. On the Tools menu, click the Account Settings option.
  2. 2. Click the account you want to edit.
  3. 3. Select the Outgoing Server (SMTP) option, then select the SMTP server you wish to edit.
  4. 4. Click Edit. A new box appears with advanced settings.
  5. If the value is 25, then remove and enter the alternate port of 587. 
  6. You may need to try both ports before you can successfully send emails.
  7. You have changed your outgoing server port.