Most of the IP addresses are blacklisted

Hi Azure,

I'm evaluating Azure VM and found out most of your IP addresses are blacklisted for the mail server(SMTP).

I use postfix and the configuration works on the other clouds(i.e. AWS, Rackspace). This is the error I've got

status=bounced (host aspmx.l.google.com[74.125.25.27] said: 550-5.7.1 [104.42.19.239      12] Our system has detected that this message is 550-5.7.1 likely unsolicited mail. To reduce the amount of spam sent to Gmail, 550-5.7.1 this message has been blocked.

Could you please help?

Thanks,