CircleID

AOl has been very progressive of all the ISPs for a long time, and a lot of the stuff they are doing is very good. For example, AOL's postmater wrote a document on port 25 blocking and it seems that they are widely promoting the idea along with allowing the SUBMIT port (587) instead. Good luck!

I'm opposed, myself, to ISPs blocking port 25 outbound, since many users (myself included) have legitimate reasons to use outside mail servers.  In my case, I use an e-mail address in my own domain, hosted on a Web hosting provider, and wish to use both inbound and outbound servers at that provider.

Need to use an outside mail server?

That's easy to do with SMTP-Authorization running on the SMTP Submission Port, TCP port 587. This can also be accomplished by using SMTP-AUTH with TLS (aka SSL). Other alternatives include SSL and IPSec VPNs. You would be surprise how many folks support at least one of these techniques. If they don't, find a new hoster!

Closing port 25 to dynamically assigned IP addresses is an important part of the move towards accountability and authentication in email origination.

For now, you can also "smarthost" - use your own ISP's mailserver to relay out mails with altered message headers. As SPF and Sender-IF are adopted, however, this will stop working, as the difference between phishing and smarthosting is intent rather than technical.