Hi, I have a mail server that appears to be struggling to send mail sporadically to hotmail.com addresses. Our domain name is hosted by GoDaddy, however the server is configured to direct send, so doesn't use a relay-host. The issue is that I am getting: to=<email@example.com>, relay=smtp.secureserver.net[126.96.36.199]:25, delay=5.4, delays=0.03/0/1.6/3.8, dsn=5.1.1, status=bounced (host smtp.secureserver.net[188.8.131.52] said: 550 5.1.1 <firstname.lastname@example.org> Recipient not found. <http://x.co/irbounce> (in reply to RCPT TO command)) I have checked that the server can resolve hotmail.com and that it is able to resolve the mx record for the hotmail domain and there is no issue. Also it isn't every message to hotmail, however it's only hotmail addresses affected. Looking at the secureserver.net domain it's owned by GoDaddy, but I can't see there would be any way that the message should be directed via their servers. Can anyone shed some light on this? Thanks in advance!