Hi there,
first - Im new on Mikrotik. Im using MAIL server (postfix) on my internal network. Everything works fine, but I have also some computers conected trough PPTP and there I have a problem with sending mails to external recipients. Everytime i get the mail back with error “Relay access denied”.
The IP adress of the local mail server is 192.168.1.200/255.255.255.0and the IP adress of the PPTP connection on the pc is 192.168.1.112/255.255.255.255 and I think there is the problem.
Can I change somehow the subnet mask of the PPTP client? Or what can I do with this situation?
It sounds like you need to edit your postfix settings to allow that ip to relay email. You should be able to check your postfix logs and see what ip postfix is rejecting.
I use sendmail so I am not sure I can help you with the actual entries.
you cannot set /24 as tunnel address. So, just check your configuration. Exim4 user here, and usually to allow connections i can set just network, and then users that match in that network can send e-mail through the server, something like, 10.0.0.0/8 and everyone within can use the server, even if they are 10.1.1.1/24 or 10.1.2.1/32