On 4/21/2010 6:49 AM, Claudio Lapidus wrote:
So we are considering ways to further filter this traffic. We are evaluating implementation of MSA through port 587.
RFC 5068, Email Submission Operations: Access and Accountability Requirements, is a BCP. It specifies authenticated port 587 for email submission across the net.
As others have noted, it works well through a wide variety of access environments. I don't remember the last time I found it blocked. I use it over TLS, of course.
Blocking of outbound port 25 for all hosts not explicitly authorized has become common. The fact that 587 default to authenticated is the win.
d/ -- Dave Crocker Brandenburg InternetWorking bbiw.net
