My OS is Mavericks. The mailboxes shown are grouped under headings MAILBOXES, SMART MAILBOXES, ON MY MAC, and MY EMAIL ADDRESS. I have Sent and Trash under each. Their contents are not entirely duplicative. When I go to mailbox/use this mailbox as, the options are grayed out. In Preferences/Accounts/Mailbox Behaviors all options are checked to 'store messages on server'. How do I combine these mailboxes?
Thanks,
Rick
MacOS – How to combine multiple mailboxes in Mail.app
imapmacosmail.app
Related Solutions
This appears to have been a hiccup on the SMTP server.
Mail does have an action called "Archive" in the Message menu that moves the current message in to a directory called "Archive." I use it all day every day on my work IMAP account just like in Gmail. I stash everything in there and just rely on search to find what I need. It works great.
I don't think there's a way to remap the Delete key to perform an Archive action instead, but Archive does have a keyboard shortcut: control-command-A. If you find that as clunky as I do, you can remap it in System Preferences' Keyboard pane.
You can also add Archive to your toolbar if that's more your thing.
Best Answer
In the Menu Bar, go to Mailbox after selecting the sub-mailbox, one of your Sent folders, for instance, and then choose "Use This Mailbox For…". You can lump the redundancies together this way, but it's true that you will not be able to completely customize all the boxes.