Mail.app in Sierra accumulating Gmail drafts [duplicate]

Just now using MacOs Sierra's Mail client. Compared to what happened on El Cap, which worked fine. It seems that now Gmail is accumulating drafts, in other words, once the email is sent, there may be one or many drafts of the email in the drafts folder. Probably corresponding to how many autosaves happened.

Can I stop this from happening?

I had just fixed this problem in El Cap when I updated to Sierra, and it came back in full force. The solution is simple though. In this version of the Mail app there's no more checkbox for saving drafts on the server, but you can manually select where Mail stores your drafts for you.

As before, go to Settings > Mailbox settings and in the Drafts drop-down menu select either [Gmail]/Drafts or [On my mac]/Drafts.

Selecting the latter option will prevent Mail from sending your drafts to the Gmail server, resolving the problem with leftover drafts.

Obviously, this does mean that you can't work on your Mail drafts in the Gmail web version.

I don't know if it's just a Sierra issue, but I experienced the exact same thing when I upgraded to El Capitan. That's what happens when you check "Store draft messages on the server" in Mail > Preferences > Accounts > Mailbox Behaviour.

I fixed the issue in the following way: Uncheck the checkbox for the drafts. You won't be able to see the same draft email on multiple devices, but you'll avoid this annoying behaviour. You can also set, at the Gmail web interface, the Gmail "Drafts" folder not to show in IMAP so that you won't have an extra, unneeded Drafts folder.

This happens on gmail and on exchange/office 365 for me. It happens on and iOS for me too I addition to macOS so I just delete them later. I can't tell if it's intentionally designed on the gmail / exchange side or an optimization when you connect to a load balancer and don't have one actual server to send mail.

Apple's iCloud seems to handle this better and you could always run an on-premesis outbound mail server if you cannot allow drafts to accumulate or just clean them up periodically or disable saving drafts to the server.

My long term solution was to move my personal mail to iCloud and my business mail to FastMail. No more google and their take on IMAP has made my life with native mail clients much better.