simonw at zynet.net
Fri Sep 5 03:21:17 CDT 2008
On Friday 05 September 2008 00:33:54 Mark Foster wrote:
> *rest snipped*
> Is the above described limitation a common occurrance in the
If the ISP blocks port 25, then the ISP is taking responsibility for
delivering all email sent by a user, and they have to start applying rate
limits. Otherwise if they send all email from their users, all they've done
is take the spam, and mix it in with the legitimate email, making spam
Locally one of the big ISP insists you register all sender addresses with
them, so all the spam from them has legitimate sender credentials.
The problem is that by blocking port 25, you are basically then switching
users to arbitrary per ISP rules for how to send email. This is probably good
for ISPs (provides some sort of lock-in) but bad for their users.
Whilst the antispam folk think it is a godsend because their block lists are
smaller, it is relatively easy to block spewing IP addresses, and hard to
filter when good and bad email is combined. Which is why they hate Google
hiding the source IP address.
This will continue until the real issue is addressed, which is the security of
end user systems.
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