My me.com email disappeared and I cannot "restart" it
I have been working on this for several weeks. After upgrading my HDD to an SSD, my me.com Apple Mail account disappeared. I have two Apple ID's, one based on Gmail (my original one, but not the one used for Mail) and an iCloud.com email that I use for my me.com email.
My iCloud Apple ID was recently verified (after a 6-day waiting period) but when I try to add the me.com address using the iCloud instructions, the system does not recognize it, as shown in the screenshot.
How do I get the system to verify this account?
MacBook Pro 13″, macOS 10.15