So for the past two (?) days I’ve been without email at my own domain!
1) Long story short (too late!) my domain straddles two ISPs. One upgraded a server, so the other was sending email to the OLD server - in other words, it was sending email into the ether and not to me.
2) This took a little longer to resolve since I had forgotten ALL of my login information for the second ISP. Attempts to verify my identity by calling me on my landline led to the surprise of (after unplugging my router modem thingy - whatever they’re called now) and replugging in my Dimmick Supply pushbutton phone from the 1970s - there was no dial tone.
2a) Had to verify by landline because they wanted to send a new password to the email associated with the account - which was one of the affected email addresses.
3) NOW I am able to send and receive email again - huzzah! - but, it seems, not through whatever the email system is on my computer, but through the web interface. Again, something about passwords.
Bonus: So if you DID send me email in the last two days, I didn’t get it, and please resend. Thank you!