Deleted email won't go to trash mailbox.

Have you told the mail server delete emails when you have deleted them? I think you need to go to Mail > Preferences > Accounts and the advanced tab to do this.

Try rebuilding the mailbox. This can take awhile if you have a lot of mail.

Rebuild mailbox

If the problem is still there, try booting into the Safe Mode using your normal account. Disconnect all peripherals except those needed for the test. Shut down the computer and then power it back up after waiting 10 seconds. Immediately after hearing the startup chime, hold down the shift key and continue to hold it until the gray Apple icon and a progress bar appear. The boot up is significantly slower than normal. This will reset some caches, forces a directory check, and disables all startup and login items, among other things. When you reboot normally, the initial reboot may be slower than normal. If the system operates normally, there may be 3rd party applications which are causing a problem. Try deleting/disabling the third party applications after a restart by using the application un-installer. For each disable/delete, you will need to restart if you don't do them all at once.

Safe Mode

Safe Mode - About

Hello Joseph,

This is my advanced panel. How does yours differ.

Having said that, If this doesn't prompt you in the right direction, Eric Root's advice is always sound. You should try it.

You are welcome.

If this is a n IMAP account, you probably won't have the option to remove from server.