mail quits upon opening, I tried restarting in safe mode and persists

1 - Restart in Safe Mode. This will perform a Disk Repair, clear cache files and only load Apple Software, extensions and fonts. The boot up will be slow and can take some time - Normal.

2 - Does the issue present in this mode ?

3 - Sometimes a Safe Boot followed by a Normal Boot will just put things right.

4 - With Mail closed, Shift key and click Mail - this is an " application " Safe Mode

You are welcome and thank you too.

Do come back to the Apple Support Communities ( ASC )  in the future, if / or when additional questions may arise

Great and file it way for future usage for most other applications if it will not Strat normally 😀