I run an exchange 2003 enterprise edition server behind a firewall (m0n0wall) on a high speed ADSL server connection. I have absolutely zero issues. therefore i figured that i should be able to duplicate my efforts for one of my clients. First mistake.
my client is running MS SBS 2003 with exchange as well. they only have a SOHO ADSL package with the same ISP. this package blocks port 25, for obvious SPAM related issues. they can send internal messages fine and also messages to the outside world seem to be OK as well, but anything sent to an address with their ISP's extension (ie...***@TELUS.NET) comes back with the 5.1.1 permanent error message.
what i would like to know is this, would upgrading their ADSL package to the same one that I have, be enough or am I missing something? I am open to any suggestions here seeing as i already look like a fool to these clients and would like to close the book on this one rather ASAP (hence the points)