I use macOS Mail in Catalina, and I noticed a frequent issue with my Gmail account disconnecting and not updating messages for that account. This would occur at least daily.
My research suggests that this repeated disconnection could be related to the fact that I did not have the Google Calendar synchronizing (I actually use iCloud Calendar for better Siri integration). After I configured my Mac to sync the Google Calendar, the connection issue with Gmail seems to have been resolved.
But what if you don’t want the Google Calendar entries cluttering your macOS Calendar? Thankfully, that’s a fairly easy fix, too.
Sync Your Google Calendar
- On your Mac, open System Preferences.
- Click Internet Accounts.
- Click Gmail.
- Verify that Calendars are set to synchronize. If needed, click to add that checkmark.
Hide Google Calendar Entries
- On your Mac, open macOS Calendar.
- In the upper left, find and click the Calendars button.
- In the list, uncheck all the boxes under the Gmail section.
Hope this works for you!