Forcing shows a DNS error: it is like it's trying to lookup domain' (with ending ').
The other emails in the queue are deferred consequently.
Any idea where the ‘ is coming from?
I see that the name (not the e-mail address) part has only a single quote ‘
and this quote probably breaks up the string evaluation (the single quote ‘ is wrongly seen as a delimiter but shouldn’t be because it is within the “ “ double quotes!
This is considered as a bug, because in the name part the ‘ is NOT a forbidden character at all (RFC)
the To: field has been compiled with the ' character surrounding two email addresses (test1... and test2...), and this has caused sendmail be unable to extract the server name correctly, hence the DNS error.
The envelope sender, the From:, the To:, etc. fields, and all the email addresses in the Sender and Recipient columns in tables, are “cleaned” before being displayed. The message header is shown as it comes, without any processing.
In all the emails in the outgoing queue there is at least one email address in the format <’firstname.lastname@example.org’>