[HECnet] Comcast Email Blocking

[Brett Bump]

On Tue, 12 Feb 2013, Dave McGuire wrote:

On 02/12/2013 03:50 PM, Brett Bump wrote:
I'm not sure what the routing issue are with *Comcast*, however Johnny is
right about them not having "some" access to the rest of the internet.   We
have been blocking email access FROM *Comast* for years because of all the
spam that comes off their network.   My last access edit for CMCS was:

-rw-r--r-- 1 root wheel 6958 Apr 20   2008 CMCS

# CMCS             Comcast Cable Communications, Inc.
#------------^------------------v--------------------------------------#
24.126                                                   550 Spam not wanted (CMCS)
<snip>

I block 115 class B subnets from them (that's 7536640 IP addresses).

Are you differentiating AT ALL between their consumer connections and
their business connections?   If not, that's a really bad idea.

No, actually, I am not.   And I would agree, "IF" there were any business
connections between the users and Comcast, however these are students. The
"acceptable use" agreement with the students is that they use their email
accounts and the internet connections for college classes.   Every once in
a while, there ARE certain networks that I need to open back up, but this
is rare (recently a user wanted access to Bank of America on APNIC).

That said, my mail server handles about 100 users and 24 domains, most
of which are businesses.   It moves, on average, about 6500 messages per
day.   Not being able to email Peter directly is the first issue I've had
in a year and a half of having this connection.

So, I am forced to ask: WTF?

                            -Dave

Our school email server handles on average 15k email per day for 3774 user
accounts.   We've blocked 1288 email from CMCS in the last month and of all
of the domains we block, 288896 since Jan 13th (and still we get spam).

As for wtf, I would venture to say that some of these networks do not know
how much spam their customers are generating.   I would love to block Yahoo
however we do have some students that communicate with their instructors
via that network from their homes.

But the school is a different entity than the other domains that I manage
and is the only one that I know of (knock on wood) that is blocking Dave.
And dont' feel bad Dave, as there are many networks that block our School.

Brett