On 4/24/07, Drew Broadley <drew@broadley.org.nz> wrote:

Simon,

After releasing Clever Toys (yeah yeah, hate me later) all registrants
but two hotmail addresses have had their mail silently discarded.

I'm getting a DSN of 2.0.0.

pr 24 18:11:13 ct-http sendmail[56230]: l3O6BDKf056230:
to=xxxx@hotmail.com, ctladdr=www (80/80), delay=00:00:00,
xdelay=00:00:00, mailer=relay, pri=30767, relay=[127.0.0.1] [ 127.0.0.1],
dsn=2.0.0, stat=Sent (l3O6BDnU056231 Message accepted for delivery)
Apr 24 18:11:15 ct-http sm-mta[56233]: l3O6BDnU056231:
to=<xxxx@hotmail.com>, delay=00:00:02, xdelay=00:00:02, mailer=esmtp,
pri=30888, relay=mx3.hotmail.com. [65.54.245.72], dsn=2.0.0, stat=Sent (
<40ab9b994bb5975132b6aa1e8c84d470@127.0.0.1:8808> Queued mail for delivery)

My local MTA happily accepting, then hotmails MTA happily queueing. No
bounce backs, nothing.

I will add another beer to the one Simon offered.

- Drew

I've been seeing this on quite a lot of systems.

I think the problem lies in the two factor spam protection that Hotmail uses. They use Brightmail and also their own inhouse systems. On some occasions it appears that either an IP address or spam message is identified as spam somewhere along the line and is just getting dropped after already being accepted for delivery.

I suggest you sign up for SNDS to see some information about what your IP blocks are sending to Hotmail.

https://postmaster.live.com/snds/index.aspx

Also make sure to have a good read through all of the information on

http://postmaster.msn.com/

But really, Hotmail is Hotmail, and they'll do whatever they damn well please, and while I don't agree with accepting a message and then not delivering it,  I really can't blame them.
Tell your users to tell their friends to stop using hotmail and start using gmail or some other less-spam-blocky alternative :)

In the end hotmail is a free service, and you get what you pay for.

Cheers,
Blair