I use mac mail and haven't had any issues with gmail delays (desktop or mobile)
on Sierra
I had to switch to Outlook in the summer. Had enough!
Don't be fooled by a free one called SPARK. It's shite.
Ive been using Airmail 3 and I love it
Postbox is also goodness. No issues with a couple of Gmail accounts and a sodding Outlook one.
https://postbox-inc.com/
Apple Mail is pish.
I'd switch to AirMail 3.
https://9to5mac.com/2017/06/06/i…