New Email Error Message - "Sorry"

[Scooter]

Just trying to send email, anybody want to explain this one?

[ERROR] - An error occurred. Account: "mail.hughes.net", Protocol: "SMTP", Task: SMTP send all messages, Server: "smtp.hughes.net", Port: 465, TLS: Yes (1.2), Error message: "Sorry." For more details look in "Log" tab - error messages are marked in red color.

Here are the details:

> [SMTP] [2020-12-07 17:54:01] Connect to "smtp.hughes.net", Port: 465, TLS: Yes (1.2)
< 220 smtp.hughes.net ESMTP server ready
> EHLO YOUR-2CA16646B7
< 250-hughes.net says EHLO to 72.168.176.204:35836
< 250-ENHANCEDSTATUSCODES
< 250-PIPELINING
< 250-AUTH=LOGIN PLAIN
< 250-AUTH LOGIN PLAIN
< 250-SIZE 104857600
< 250 8BITMIME
> AUTH LOGIN YWh1dGNo
< 334 UGFzc3dvcmQ6
> MzkzMjBtb2Zv
< 535 5.7.8 Sorry.
> AUTH PLAIN AGFodXRjaAAzOTMyMG1vZm8=
< 535 5.7.8 Sorry.
> QUIT
< 221 2.3.0 hughes.net closing connection
An error occurred. - Sorry.

Tried to send more than once, same result.

[MarkJFine]

Try port 587 instead of 465. Some people seem to be having better luck with that for some reason.

[Scooter]

This email would continue to get rejected, with various error messages but finally went through later this week.

I hard headedly stuck with port 465, overall, I've had better luck with that, for what it's worth.

and it's continued to behave since, Wed or Thurs?