| Step 1: | Launch Mozilla Thunderbird. If it is your first time launching Mozilla Thunderbird, the Mail Account Setup Wizard should appear and you may skip to step 4. Otherwise continue with the next step. |
| Step 2: | From the Mozilla Thunderbird window, select Tools -> Account Settings.  |
| Step 3: | At the bottom-left, select Account Actions and then Add Mail Account  |
| Step 4: | Enter Your name, your full 1&1 Email address and your 1&1 e-mail address Password. Check the box for Remember password if you do not wish to enter your password every time when checking or sending e-mail. Then, click the Continue button.  |
| Step 5: | Suggested settings may be provided for you. Be sure to select IMAP to view the suggested IMAP settings. In this example, the suggested settings are incorrect so we will click the Manual Setup button to enter the correct information.  |
| Step 6: | Select the Server Settings menu option from the left-hand side under the 1&1 e-mail address you are setting up.  |
| Step 7: | Enter pop.1and1.com as the Server Name. Enter your full 1&1 e-mail address as the User Name. From the Connection security drop-down menu, select SSL/TLS. Selecting SSL/TLS should set the default port to 995 as in the image below. If not, manually enter 995 as the port number to use.  |
| Step 8: | Select the Outgoing Server (SMTP) menu option from the left-hand side.  |
| Step 9: | In this example, the suggested settings still remain with the incorrect outgoing server address. We will select the incorrect 1&1 outgoing server and click the Edit button. If no suggested settings were entered, simply click the Add button to manually add the outgoing server.  |
| Step 10: | Enter a Description of the outgoing server. This is simply to identify each outgoing server in the scenario where many e-mail accounts are added to Thunderbird and each account uses a different outgoing server. Enter smtp.1and1.com as the Server Name. Enter 587 as the Port. Select STARTTLS from the Connection security drop-down menu.  |
| Step 11: | Enter your full 1&1 e-mail address as the User Name and click the OK button to save your settings.  |
| Step 12: | Select your 1&1 e-mail address from the left-hand side.  |
| Step 13: | From the Outgoing Server (SMTP) drop-down menu, select the 1&1 Outgoing server (smtp.1and1.com) and then click the OK button to save your settings.  |
| Step 14: | You should now see your newly added account on the left-hand side of the Mozilla Thunderbird window as you account is now fully set up!  |
