Hi all. My first post here, I hope this is the right place!

I recently setup a postfix server as I needed an smtp server. In order to allow my local machine to send emails through it as a relay I added something like:

xxx.0.0.0/8 to the 'mynetworks' variable in main.cf, where xxx are the first three digits of my local IP.

This works for now, but as soon as my ISP switches up my IP postfix will again block me out. I tried using a domainname that is always mapped to my dynamic ip in place of the numeric IP, but it didn't work.

Any ideas on how to deal with this?