We were able to resolve our error by removing the trailing comma, but I wanted to share the report of the problem here in case it is worth filing a bug for or fixing.
I saw also this ticket that might be related:
LDEV-2234
This is coming from 5.3.8.53-SNAPSHOT onwards([LDEV-2234] - Lucee). This is the commit that causes this issue fixes LDEV-2234 · lucee/Lucee@2f3f57f · GitHub. Trailing comma that works fine before 5.3.8.53-SNAPSHOT from the above commit trailing comma causes this issue.
we had similar messages ‘Attribute [from] of the tag [mail] is invalid’ in breaks where we had commas in the display name of from address, causing a full break. previously these didn’t break completely. not looking for any change, just want to share observation.
appears to be working correctly for us in all versions
emails like: "blah, inc" <noreply@blah.com>
some occurrances someone had changed to appending together vars together, which dropped the quotes wrapping the display name portion, resulting in emails like: "blah, inc <noreply@blah.com>"
we fixed our code, and weren’t going to complain about it, because we considered the missing quotes wrong, but it definitely was a behavior change.
up through 5.3.7.47
would send an email as if the from was: inc <noreply@blah.com>