In the Exchange 2013 Web console, how do I disable SMTP relay so spammers can't use that old trick of sending to a non-existent Exchange address to generate an outbound NDR? Thanks.

On Sat, 23 Feb 2013 18:13:24 +0000, emr88 wrote: >In the Exchange 2013 Web console, how do I disable SMTP relay so spammers can't use that old trick of sending to a non-existent Exchange address to generate an outbound NDR? Thanks. Enable recipient filtering and reject e-mail sent to addresses not found in the directory. --- Rich Matheisen MCSE+I, Exchange MVP --- Rich Matheisen MCSE+I, Exchange MVP

Hello, By default, when an exchange 2013 Client Access server is installed, it is pre-configured with a Receive Connector named "Default Frontend <servername>" which anonymous users are enabled on. If you disable SMTP relay, you can disable anonymous users. If you have any feedback on our support, please click here Cara Chen TechNet Community Support

Cara--- Thanks, I cleared the "anonymous users" checkbox in the "Default Frontend <server>" receive connector. That should prevent SMTP relay, correct?

Hello, Yes. If you have any feedback on our support, please click here Cara Chen TechNet Community Support

Hello, By default, when an exchange 2013 Client Access server is installed, it is pre-configured with a Receive Connector named "Default Frontend <servername>" which anonymous users are enabled on. If you disable SMTP relay, you can disable anonymous users. If you have any feedback on our support, please click here Cara Chen TechNet Community Support

wont this just stop outbound servers being able to connect to actually send email to the guys server?

Yes it will. This will result in NO email being delivered. So what is the answer? Does anyone have a clue? My server is getting hammered with NDR.

On Sat, 13 Apr 2013 20:54:41 +0000, TCMagic wrote: >Yes it will. This will result in NO email being delivered. So what is the answer? Does anyone have a clue? My server is getting hammered with NDR. You can publish SPF information in your DNS. It won't stop address spoofing but it will reduce it. Do you rely on Exchange for anti-spam scanning? You could refuse to accept e-mail from your own domain. You could do that with a transport rule, too. --- Rich Matheisen MCSE+I, Exchange MVP --- Rich Matheisen MCSE+I, Exchange MVP