First off, the IP address of your mail server cannot be dynamic (DHCP), it must be static. Assume 10.10.10.1 is your mail server and Ethernet1 port 23 (UDP and TCP) are your external interface. This will map anything that comes in on port 23 to that internal ip as well as port 23.
Hopefully that solves your problem... I have used the above lines as solution to your exact problem.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.