Merit Network
Can't find what you're looking for? Search the Mail Archives.
  About Merit   Services   Network   Resources & Support   Network Research   News   Events   Home

Discussion Communities: Merit Network Email List Archives

North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: ( /24) blocked by for SMTP

  • From: Alan Spicer
  • Date: Sat Sep 24 21:50:20 2005

----- Original Message ----- From: "Omar Thameen" <>
To: <>
Cc: "Suresh Ramasubramanian" <>; "Alan Spicer" <>
Sent: Saturday, September 24, 2005 6:25 AM
Subject: Re: ( /24) blocked by for SMTP

On Tue, Sep 20, 2005 at 09:01:40AM +0530, Suresh Ramasubramanian wrote:
On 20/09/05, Alan Spicer <> wrote:
> I wonder if anyone with can tell me why this ip or /24
> ( /24)
> would be blocked from sending SMTP to customers.

That's a large (and quite good) webhost called, which also
hosts the Pittsburgh IX (

Blocking is fine - happens.  Postmaster and other role accounts not
replying at all to email that they're sent is just not a good thing to
This may give you an idea of what issue may be and the response
you're likely to encounter.

Back in June, we contacted Bellsouth postmaster regarding their
filtering of SMTP connections (i.e., so that connection attempts
hang until the timeout is reached), and received this reply from

We will configure our settings for your company on our
Filtering mechanism to 50 messages within a 5 minute window.
We ask that you conform to this industry standards regarding
submission of email to our mail server.

As you all know, 50 messages/5 minutes is abysmally low, particularly
for a mailing list hosting provider.  Our requests for higher
threshold and a pointer to the "industry standards" were summarily

If there's a Bellsouth contact with more of a clue on this list,
we'd be happy to meet any reasonable requirements you have for email

Omar Thameen

Bellsouth basically told me they were blocking Pair Networks because
the percentage of spam vs non-spam is around 75 - 80%. They say
they are communicating with them on this. Supposedly there was a
conference telephone call this past Thursday 09-22-2005. BS says
they must reduce this spam amount for the block to be removed.

Pair seems to think it is mostly domain customers forwarding their
mailboxes to their BS dot Net email accounts.

This the first I've heard of BS having a 50/5 threshold limit.

Alan Spicer (

Discussion Communities

About Merit | Services | Network | Resources & Support | Network Research
News | Events | Contact | Site Map | Merit Network Home

Merit Network, Inc.