Hello everybody,

how can I block a incoming mail adress ???
Thanks for your help.

Thomas

Do you want to block the IP address of the SMTP server or or you trying to block a specific email address?  

If you want to block the IP address of the remote SMTP server, create Network Entity host entries for each host or subnet to block.
Create a Network Entity group call blocked-smtp-servers and add all these newly created hosts and subnets.  

Create a new Deny access to Services rule with connection from <DMZ NIC> from Source block-smtp-servers Destined for <your mail server> coming out <appropriate interface>
On the Service tab, include *smtp service.

I use this setup to block subnets of spammers that use several IP addresses within a subnet.  The group can also include hosts, too.  

To filter logfile to see results:  Search component gwcontrol and Text explicit deny