Email Rejection Blues

Hello again, Gnomies. Sorry that I dropped off the posting radar again — seems to be a bad habit of mine. My wife and I adopted a puppy, and our lives have changed forever. Curtis is a Miniature Pinscher-Fox Terrier mix, and boy, is he full of energy. If you care to check out the little guy, go to his Picasa gallery here. But I thought I’d take advantage of a few slow moments today to write a new post (hopefully that will get me back into the swing of things).

I have an old client of mine that I helped move their mail hosting over to Google Apps. And being one that subscribes to the philosophy of eating ones own dog food, I moved my own mail hosting over to Google Apps beforehand. I found Google’s documentation to be very well written and the process went smoothly for both my own move, as well as for my client. And over the long haul, both she and I came to appreciate the generous email quota as well as other aspects of Google Apps, such as gCal, etc. True enough, there have been a few outages, but I don’t think they were any more frequent than other customers I have on hosted Exchange or even enterprises I work with that have internally managed email systems.

Fast forward to today, and the one problem that has surfaced for this client is problems getting email from. More specifically, whenever somebody with a address attempts to send her an email, it is quickly rejected. Here’s the gist of the NDR I got when I sent her a message from my own hotmail account (I’ve removed the recipient’s email address for privacy):

Reporting-MTA: dns;
Received-From-MTA: dns;BAY106-W3
Arrival-Date: Tue, 10 Mar 2009 13:39:15 -0700

Final-Recipient: rfc822; [email protected]
Action: failed
Status: 5.7.1
Diagnostic-Code: smtp;550 5.7.1 Unable to relay for [email protected]

Keep in mind that both myself and this client have mail hosted with Google Apps. Our MX Records for our respective domains are identical, setup exactly as Google support docs recommended.

Priority Mail Server

Now here is the really odd part. I can successfully send myself messages from my hotmail account to my email hosted at Google Apps ([email protected]).

So why is it that hotmail messages sent to my client get rejected, when messages coming from to my Google Apps hosted email get through? Especially when the MX records for each domain are the same?

Keep in mind, we are both using Google Apps Free Edition. Google Apps Premier Edition does have Postini functionality, which allows for some policy-based control over email delivery. The free edition does not.

Strange, huh?