Mac has multiple draft emails with Gmail on Server

In your question you wrote -

When replying to an email message, Apple Mail stores multiple (sometimes 100's) of versions of the draft email and *DOES NOT DELETE THEM* when the message is sent. Apple mail is configured to keep drafts on the server, which is what I want to happen, so that I can sometimes finish them on other devices. This behaviour is NOT present when using any other device, so the bug is specific to Apple Mail on Mac, (not iPhone or iPad).

When a mail is composed only one draft is automatically saved and not hundreds or more .

If you close the compose window , and click on save button a single draft is saved and not hundred's , if you have already stored hundred's of mails as draft they will be always stored until you discard them or delete them , this is the way apple mail application works , a link is already there on the thread for sending your views to apple ie . feedback ,you can send it .

In your computer something is wrong you can delete the account and configure it once again , make sure what ever settings are changed in webmail server and are saved they will be permanent , if you delete the apple mail application multiple times and add it once again , the settings will show their impressions and consequences will be permanent .

An article for it Set up Mail with email accounts - Apple Support

For Mac , data storage is more as compared to iPhone and iPad .

If you enter in web mail compose a mail and fill up the credentials , and close the mail compose window the mail is stored as Draft on the gmail server , and if you want to discard it and delete it you can .

And if you want to delete to delete one draft or all of them click on drop down arrows and select as all .

And , if you have simultaneously opened , mail application window and dragged side by side to web mail ( gmail account window you can see the draft mails will be deleted in front of you ) .

Also , in labels you can hide or show them .

And regarding the threads you have posted , members are showing the method on apple mail application not to save drafts , but that is for El - Capitan or previous versions in recent Mac OS High Sierra , the pattern has been changed .This is just a screen shot for Mac OS high Sierra .

See some articles Save draft emails - Apple Support

Mail Mailbox Behaviors preferences - Apple Support

And in your original question that you have asked is drafts will automatically get saved when mail is composed , the purpose of storing is if you want to do any kind of changes in it in future add some subject or delete some sentences etc , its just for convenience for the user .

This exact situation has been bugging me for years and I completely understand your situation. The 'answer' above isn't an answer and as you point out - the workaround is to not use the functionaity that you are trying to use...... hmmm.

When I've researched this before, it turns out that the protocols used by mac mail and gmail aren't 100% suited to work together. I's something to do with how drafts work and auto-save What Google use is geared up to work for their own online email service and as a result the draft folder in Mac Mail is left accumulating drafts as they are auto-saved.

So, if you create an email, Mac Mail will, by default, auto-save every so often. Each of these auto-saved is stored on the server but (due to the incompatibility) not overwritten.

Result = lots of saved drafts. Only the 'final' draft gets removed when you send.

Apple will argue that they have created an Email Application that is designed to work on their own platform and therefor ask Google to correct this. Ask Google and they will say they are focusing on making their own system work. You get the picture.

It bugs me, but as far as I know, there is no way to make this one thing work. Technically it isn't a bug, as both Apple and Google will say their email is working exactly as they intended.

Send Apple feedback. They won't answer, but at least will know there is a problem or a suggestion for change. If enough people send feedback, it may get the problem/suggested change solved sooner.

Mail Feedback

Hello !

There is no such as settings in gmail web account , if you click on that button and will not save your drafts , you can only unhide in labels , go to the settings > Labels > then hide the drafts box and finally click on save .

Apple mail application is just configured with gmail web account .