Comment Wow, what a bunch of clueless responses (Score 1) 263
A very restricted SPF TXT record that specifies _precisely_ which IP addresses an incoming SMTP for a given domain an email _must_ come from cannot hurt. At best, your IT admins have wasted a half hour, at best they have significantly improved the chance of your outgoing email being not treated as suspicious by bulk email handlers such as yahoo, gmail and hotmail (especially hotmail).
You want proof? Check your shit. http://postmaster.live.com/Services.aspx . And no, I don't work for MS, but damn they provide the best postmaster tools on the interweb for monitoring shit like email deliverability. Don't even talk to me about the pestilence that is Yahoo!, those pricks remind me of my evil DM who used to make up pointless forms just to pass the time.