hi, i'm a newbie using slack 10.2

can anyone help me with port forwarding on a huawei smartAX 882 router? & can it automatically update the IP address? since i don't hav a static IP. I hav gone thro' the manual, but it didn't help much, i hav given my local pc IP address in the "virtual server" part of the router configuration, but after i save the settings it is reset to 0, mine is NOT a static IP

i got to know how to setup a mail server from http://shilo.is-a-geek.com/slack/netprep15.html
i hav signed up on the dyndns.org website & am using the ddclient shell script to update the IP, now i can send mails frm my comp using 'pine' the only thing is i can't recieve any mails.