I had just finished deleting a group of messages from my inbox and as I sat watching my monitor several other messages that I wanted to read were being deleted without my ever clicking on anything.
They were not moved to the Trash or Junk folders. They just magically disappeared.
What’s up with that?
That could sometimes mean another device or computer is configured to the same eg: IMAP, Exchange, iCloud account and someone is deleting your emails without your knowlege.
Maybe a family member or someone else unknown who has access to your account or your computer if its logged in or been compromised.
I would suggest to change your email account password online & update eM Client with the new password and see if the problem stops.
Otherwise if changing the password makes no diferance, then you might have a eg: Sticky or Faulty “Del” key on your keyboard. Try spraying some electronic cleaner in your keyboard and see if that fixes it as it might be sometimes stuck down without you knowing. Failing that try another keyboard.
Those are all good ideas but what happened to me was I had just highlighted a group of emails from my inbox and when I picked “Delete” from the the top of the page and then “Yes” to confirm the request the system did in fact delete all of the messages I had highlighted but it didn’t stop there. The odd thing is that typically when I have deleted any messages from my inbox they move to the Trash folder. Those extra messages that I did not pick did not go to the Trash folder or any other folder. They simply disappeared. All of the messages that I did highlight did go to the trash folder and are still there. I also checked my Yahoo mailbox on-line and the extra messages that I did not highlight are also gone from the Yahoo server.
BTW, no sticky keys and no one else that I am aware of has access to my computer or my email accounts. Besides, wouldn’t it also be quite a coincidence for someone else to be deleting messages at exact same time as me?