Select Accounts from the Mail menu. Uncheck any accounts you don’t wish to use with Mail. Emails downloaded from those accounts will be removed.
Your deleted message will be sent to the Trash or permanently removed, depending on your app’s settings. It’ll be really time-consuming if you have to go through the process, again and again, to get rid of all of those unnecessary messages in your Mail app.
To change where email account draft, sent, garbage, deleted, and saved messages are kept, use the Mailbox Behaviors preference in Mail. Select Mail > Preferences then Accounts, then choose Mailbox Behaviors from the drop-down menu in the Mail app on your Mac.
The messages are being deleted due to a Mail rule or junk filtering. Another gadget that is linked with the same IMAP or Exchange account is deleting the mail. The account may be accessed via both the IMAP and POP protocols, which can happen if certain mail servers?
Select Properties from the context menu Right-click the mail folder where emails are automatically deleted and choose AutoArchive from the options. Check Do not archive items in this folder under the AutoArchive tab in the Properties dialog to disable it.
