We’ve seen more of our customers running into silly port 25 blocks thrown up by their home ISPs. Some of the ISPs that practice this, and an explanation of the problem, are here: http://blog.dreamhosters.com/kbase/index.cgi?area=1623.
If your ISP is blocking port 25 and you’re seeing error messages like “mail.example.com not responding” or “not found” when trying to send messages through your domain’s Utopian.net SMTP server, you can change your email client settings to send outgoing mail to the SMTP server on port 587 instead of the usual port 25. Port 587 is the internet-standard submission service port, defined by RFC 2476.
Using port 587 for SMTP should allow you to send mail from your domain (once you’ve authenticated as usual with your email username and password), even in situations where your outbound port 25 is blocked.
Then you can use your restored access to mail your ISP and tell them how little you appreciate them censoring your network access without even asking.
[...] and Labs moonlighter Tim Hamilton has whipped up a couple screencasts showing how to make the changes to your SMTP server port settings described in our last post. If your ISP is blocking your outbound port 25, Tim has videos for both Microsoft Outlook and [...]
[...] (subtraction?) to already blocking your access to the services they decide they don’t like, like your own site’s email servers, or BitTorrent and other social technologies.The initial cap may seem high, and you might not even [...]