When using POP, Thunderbird doesn't delete mail with large attachments off server.
Overview: - Latest version of Thunderbird - AT&T email (Yahoo backend) using POP (SSL port 993)
Using POP, normally Thunderbird downloads the email and deletes it off the server and goes on to the next email. A problem arises if the email has an attachment that is larger than 1MB. Thunderbird downloads the email with the attachment but is doesn't (or is unable to) delete it from the server and never downloads any emails that came after it. When you check mail, Thunderbird just keeps downloading the same email with large attachment.
Does this sound like a problem with Thunderbird or is it a problem with the Yahoo mail server?
Alle svar (1)
This sounds like a problem with your anti virus. not Thunderbird or Yahoo.
Try disabling email scanning and see if these mails get deleted. I think you will find they do.