Map the external IP address to an internal IP address in your router and then use the internal to bind your ports and domains.
Just remember to map the FQDN HOSTNAME for your SmarterMail server to the public IP address in the host name mapping.
Bruce Barnes
ChicagoNetTech Inc
brucecnt@comcast.net
Phonr: (773) 491-9019
Phone: (224) 444-0169
E-Mail and DNS Security Specialist
Network Security Specialist
Customer Service Portal: https://portal.chicagonettech.com
Website: https://www.ChicagoNetTech.com
Security Blog: http://networkbastion.blogspot.com/
Web and E-Mail Hosting, E-Mail Security and Consulting