On Oct 22, 2009, at 6:14 PM, Lyndon Nerenberg (VE6BBM/VE7TFX) wrote:
My experience is that port 587 isn't used because ISPs block it out-of-hand. Or in the case of Rogers in (at least) Vancouver, hijack it with a proxy that filters out the AUTH parts of the EHLO response, making the whole point of using the submission service ... pointless.
We use 587 quite a lot (with SMTP Auth and SSL/TLS), and have found _very_ few places block or proxy it. We don't have any/many customers in Rogers service areas though.
The biggest reason people don't use it is that it requires some thought and tweaking settings in the "advanced" tab areas of many email clients. Newer email clients are actually starting to look for submission port and SSL support and configuring it autmatically if they find it.
Once it's set up correctly we've found customers really like it since their email "just works" in most places.
--Chris
