Hello,
Just an FYI for your IT department - you must have a misconfigured mail server, since the emails being sent to users are getting caught up by postfix's "reject_unknown_domain". You must have many users not receiving their emails.
reject: RCPT from outbound-dkim.eu.khoros-mail.com[34.255.61.190]: 450 4.1.8 <no-reply@community-mail.bt.com>: Sender address rejected: Domain not found; from=<no-reply@community-mail.bt.com> to=<****recepientemailaddresswashere****> proto=ESMTP helo=<outbound-dkim.eu.khoros-mail.com>
