For several days, sending emails to gmail (only gmail) has stopped working from our exchange server, the error message received "550 No SMTP server defined. Use real server address instead of 127.0.0.1 in your account." I mention that until few days ago it worked.
I tried to change the server settings, but without success, until I noticed that if I disable the antivirus, it works without problems. What anti-virus setting blocks my email? I tried to stop only the "mail shield", but it still doesn't work.
This product is installed on Windows Server 2008 R2 Standard with Exchange Server 2010.