I can't get my gmail emails to come through after catalina change how do I change I went to preferences in mail and can't figure it out

The google SMTP was going around and around; the rest were fine.

Now after awhile it is fine with a green dot next to it.

Thank you. Now I know about the connection doctor.

I had also had clicked a word “account offline” way over on the right side, just above the mail grouping and it came back online; i did this earlier.

Blessings.

Thank you for The link. I don’t know how I would find it if I had to do it later for a problem. Looks like it’s somewhere in apple support.

Blessings.