You’re welcome.
This is not a virus, nor do I think reinstalling Mail would solve it. As I said in my previous post, the problem is just that Mail is losing track of which messages have already been downloaded and/or it’s failing to remove them from the server according to your settings.
It could be that Mail has trouble communicating with the server for some reason, or it could be that there is something amiss
at the server. Some months ago, for example, Yahoo made some changes to their POP servers that caused many users to experience similar problems, and this forum became flooded with posts about it. Nothing the users could do at their end would fix it. Eventually, Yahoo acknowledged the problem (sort of) and fixed it
at the server.
The only workaround I know of is to manually remove from the server the messages that Mail fails to remove automatically according to your settings.
The other accounts on my mac are experiencing the same problem.
Are you talking about other
mail accounts or about other
user accounts here? Is the provider the same for all of them?