Apple Mail suddenly refuses to send from one particular address
Catalina v10.15.2 Mail v13.0
This one has got me stumped.
One of my (non iCloud) email addresses has after many years stopped sending.
This is where it gets weird though - it appears to be sent by showing up in sent box of Mail, in webmail and in an alternative email client (Airmail 5). Trouble is it never shows up at the destination and I don't get a bounce message either.
Weirder still if I send test email from Airmail 5 or webmail then everything works fine, including being delivered to my inbox in Mail.
I have tried all of tried following without joy:
Verified all correct server/security/password settings with domain host Hostgator
Disabled antivirus
Tried alternative laptop running earlier OS an Mail version
Deleted preferences file
Deleted account an re added
Googled it to death but can't find any other info.
Tried alternate mail client and webmail - this works so I do have a work around but I'm tearing my hair out tying to think why.
Have tried Hostgator support but as soon as I mentioned that the problem only occurred in Apple Mail of course they said that the problem wasn't theirs.
Maybe shifting domains is the answer but before I do I wanted to see if any one out there can think of anything else.
Best,
Richard
MacBook Pro 16″, macOS 10.15