BT mail servers are not accepting mail from my server. The server good standing on all reputation services and has correct SPF records, server name and reverse DNS.
this is very frustrating. Most other services have a means of notifying these issues and correcting them but not BT.
host mx.bt.lon5.cpcloud.co.uk[65.20.0.49] said:
522 IP REPUTATION BAD (please check for 109.228.55.205 IP address listing
on reputation services) (in reply to MAIL FROM command)