Blocking Port 25
New 'Xtreme' users notice shift
Some users who upgrade to BellSouth's new Xtreme 3Mbps tier are noticing the company has taken the opportunity to block their port 25 outgoing traffic
. The move isn't new, the provider began blocking the traffic for all new users some time ago, as part of an increasingly common industry standard (see our previous report
). Port 25/tcp is used for SMTP, the outgoing mail protocol. By blocking port 25 outbound traffic, ISP's force users to use only their mail servers, preventing bulk mailing from their domains via servers not under their control. Simple configuration changes can resolve most issues (see our mail FAQ
). If criticism can be levied at ISP's concerning port 25 outbound blocking, it's that they often don't clearly inform users
of the decision once made, leaving users guessing how to resolve sudden mail outages.
70 comments .. click to read
I don't pay for crippled access
I pay for Internet Access
, not crippled internet access whereby Bellsouth decides what ports I should be able to access on other systems. Personally, I think it's absurd. However, our house is served by IFITL so I don't really have any choice of going to another provider.