[Evolution] What does this error message mean?

[peter danceswithcats uk]

Hi,

I am using Evolution 3.28.5-0ubuntu0.18.04.1 on a Lubuntu machine. It has been working fine for a few weeks. My (imap) email accounts are hosted on a commercial server and I have no problems with them on other clients (Thunderbird or Sylpheed) or on webmail.

I have twice had emails fail to send from Evolution over the last few days. I get a window come up saying the following.

An error occurred while sending. How do you want to proceed?

The reported error was “RCPT TO <******@*****.com> failed: This domain is not hosted here”.

I've done a web search for the error message and looked for bug reports mentioning this.

Can anyone point me in the right direction?

Kind regards,

Peter