I have trouble sending mail to the hotmail, outlook and other domains hosted by the same provider. The problem is that my isp's subnet is on the their block list so they refuse to receive mail from the servers are part of the blocked subnet (error: S3150). I dont have any problem with any other mail server... I'd like to route outbound mail to that domain over the other smtp server (ie. gmail) which uses STARTTLS and username and password to authenticate user. Other mails should be sent by my server. In the Advanced Email Routing I add new transport: Server: myserver FQDN Domain: hotmail.com Transport: smtp:smtp.gmail.com:587In the Relay Recipients I add relay: Server: myserver FQDN Recipient address: (at)outlook.comThis setup works as expected but gmail refuse to accept email from my server because "Authentication Required". So I need somehow to send my username and password to the gmail smtp using STARTTLS (port 587) Can someone help me with it?