- Open Thunderbird.
- Right click on your email account and click Settings.
- In the Server Settings tab on the interface, you will need to change the Port setting. In our example we’re using IMAP, so we need to change the Port setting from 143 to 993.
- If your Server Type is set to POP and not IMAP, you need to change the Port setting from 110 to 995.
- If your Incoming Server and Outgoing Server setting is set to the server’s address (e.g., “c1s1-1e-syd.hosting-services.net.au”), please change it to “mail.my-domain-name.com” (changing “my-domain-name.com” to your domain name).
- Once you have done that, you also need to change the Connection Security setting to SSL/TLS.
- Now you need to change the Outgoing Server (SMTP) settings. This can be done by clicking on the Outgoing Server tab, then selecting your outgoing server and clicking Edit.
- You will be prompted with an interface that looks like the following. You will need to change the Port setting from 587 to 465, then change the Connection Security setting to SSL/TLS and click OK.