I have set up vPostMaster (which is just like postfix i believe). Also I have installed SquirrelMail.
I can perfectly receive emails but not send them other than to local users.
When I try to send an email to firstname.lastname@example.org
for example, I get this error:
Server replied: 554 <email@example.com>: Recipient address rejected: No such domain.
I belive this has something to do with the fact, that the server is behind a router.
I also believe, it is not the port forwarding, but rather the mail server configuration. (See below for the forwarded ports.)
Does anybody know how to fix this problem? I am absolutely lost and can't find the answer on google either.
PS: Here is the list of ports that I have forwarded in the router:
Global Port(s): 110
Base Host Port: 110
Global Port(s): 143
Base Host Port: 143
Global Port(s): 993
Base Host Port: 993
Global Port(s): 995
Base Host Port: 995
Global Port(s): 25
Base Host Port: 25