i was wondering if someone could assist with a strange issue we are having when sending emails to the domain Bt.com.
some emails are being rejected with this error
said: 550 5.5.0 550 5.7.1 Requested action not taken: message refused (in reply to end of DATA command
While other emails are accepted and delivered ok.
It means what sometimes the several email has to be sent a number of times for it to be delivered successfully
we have emailed email@example.com but not received a response