mail trying to log in to this stop account failed all gmail
Apple mail, all accounts have been unable to log in to SMTP,
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It's not clear to me if this is just gmail, or if this is a wider problem with other mail accounts configured locally.
As a first step, reboot, and try again.
Check the SMTP settings. There's a reasonable chance there's been a corruption here.
Check for macOS updates and upgrades, too.
See existing discussions of SMTP settings, too...