Disc full

A-b-___c wrote:

I receive this message when I try to access email Mail cannot save information about your mailboxes because there isn’t enough space in your home folder.

How to free up storage space on your Mac - Apple Support

Free up storage space on your Mac - Apple Support

If you do "Get Info..." on your hard drive/SSD, does it show the drive full?

If not full, these Apple articles may be helpful:

Keep mailboxes from getting too big in Mail on Mac - Apple Support

Free up storage space for email accounts in Mail on Mac - Apple Support

See used and available storage space on your Mac - Apple Support