I have a few cron jobs that run on my home mac machines and I like to get the notifications generated from the MAILTO parameter. Well, a while ago (I believe after the comcast acquisition of insightbb), this stopped working. I did a little debugging and it is my belief that port 25 is being blocked outbound from the comcast network. Many people speculatethis, and as a network engineer I think it is actually a good idea. First, port 25 isn’t *really* the port that you should be using for host to mail relay. I was always taught that the submission port was best practice per RFC 2476 . In practice, many folks don’t use this port simply because since as far back as I can remember documentation has always pointed end users at port 25.
So, long story short, something I wanted to do for a long time was to set up a special account under my google apps that can be used to relay and record this data, as well as be used for things like an email wild card for my domain.
I was about to embark on hacking up the postfix installs then I came across this macosxhints article.
It’s a very handy walk through of doing exactly what I wanted to do, relay mail on port 587, over ssl through my ISP to an externally hosted email account.
Very handy.