That said, I also run my own mail server at home, on a comcast consumer connection, and I use google's mail servers to proxy my outbound mail. I got in on free google apps for your domain account back during the beta... but you may be able to pull this off with a normal gmail account. Just set your mail server to forward through googles smtp servers using your gmail credentials. Not sure if this will work if your reply to address domain is not hosted by google.
What really sucks is that Comcast also blocks inbound port 25 on consumer accounts so I have my mail delivered to google and then I transfer it to my own mail server via pop/imap, in theory leaving nothing on the google servers but probably rather pointless in practice. This is what I'm reduced to unless I wan't to pay more for a business connection. There has never been any such thing as net neutrality at the consumer level here, afaict. Every internet connection I've ever had has been asynchronous and limited in some way.