mail hangs up while upgrading library with catalina

Hi ggrannis,

It sounds like you're having trouble with Mail in macOS Catalina, and I want to help.

Is it that Mail isn't opening correctly?

Try starting into safe mode, or rebuilding your mailboxes:

Use safe mode to isolate issues with your Mac - Apple Support

Rebuild mailboxes in Mail on Mac - Apple Support

Good luck.

Thanks for using the Apple Support Communities.