Take Note:

If you want o remove an email from Mozilla Thunderbird, you can easily do it but if you use IMAP, the email will only be removed form your Thunderbird email client. The email will still be kept on your mail server.

If you use POP settings. Then email will be removed from both your Thunderbird Email client and main email server.

Steps:

1. Open Mozilla Thunderbird

   

2. Open Inbox and right click on the email you want to delete and then click on the Delete Message option.