where is the best place to get advice about gmail problem on my MacBook Pro

[ann2]

Not sure if this is where I should post this. I have a gmail account set up on my MacBook Pro. When I open it with the Mail icon , it starts downloading incoming messages and will continue until it gets in the millions! I have tried emptying junk and trash and have only several hundred (from 2014) messages I've left on. Where are these coming from and how do I stop it? And it sometimes takes hours for an authentically new message to show up on my MacBook Pro, even tho it shows up immediately on my iphone and desktop computer.

Any help is appreciated.

 

[Meister]

On my rmbp neither the mail app nor outlook no thunderbird work.

Airmail has been mostly bugfree so far.