Can't add gmail account to Mail

I'm assuming that you:

• Double-checked for the correct Gmail server information for your Gmail account. Ref: Mail Settings Lookup - Apple Support
• If you have enabled two-factor authentication on your Google user account, that you use a Google-provided specific app password, instead of your normal Google password, with the Gmail account that you are using in the Mail app. Ref: https://security.google.com/settings/security/apppasswords
• Disabled any AV or VPN apps before attempting to add your Gmail account.
• Booted up in Safe Mode to try to add the account.
• Created a new user account on your Mac. Logged out of the original account, and then, logged back in with the new account. Then tried adding the account.

If you have already done all of these, then something else (obviously) is amiss. FWIW, I have a number of Macs, running everything from OS X High Sierra to macOS Monterey. All of them have been configured to access my Gmail account in their respective Mail app ... and all are working as expected.

Give this a try: boot into Safe Mode according to How to use safe mode on your Mac and try to add the Google account from there. Reboot normally and test the account (if successful in adding the account).

NOTE: Safe Mode boot can take up to 3 - 5 minutes as it's doing the following; 

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files

ghost19_phew wrote:

Whether I go to Mail Preferences or though System Preferences and try to add my gmail account to my list of email accounts on my MacBook Pro I can't add it. I click on the Google icon and enter my username and password and then check off the apps I want to add to this account such as mail, calendar, notes etc and hit done. It freezes at that point and my only option is to hit cancel, the account isn't added and I'm back where I started. This has been going on for a week or so now and even my IT guy can't fathom it out. I'm on Big Sur if that helps. Thanks for your help - whoever you might be!

Is this an IMAP account or POP..?

You can try "Other" and set it up manually if you have an issue with the "Google" icon.

You can try the wizard..

Mail set up wizard https://support.apple.com/mail

Add email accounts in Mail on Mac - Apple Support