Microsoft using Spamhaus Lists

An on the ball reader sent me a note today showing a bounce message indicating microsoft was rejecting mail due to a Spamhaus Blocklist Listing.
5.7.1 Client host [10.10.10.10] blocked using Spamhaus. To request removal from this list see http://www.spamhaus.org/lookup.lasso (S3130). [VE1EUR03FT043.eop-EUR03.prod.protection.outlook.com]
The IP in question is listed on the CSS, which means at a minimum Microsoft is using the SBL. I expect they’re actually using the ZEN list. ZEN provides a single lookup for 3 different lists: the SBL, XBL and PBL. The XBL is a list of virus infected machines and the PBL is a list of IPs that the IP owners state shouldn’t be sending email. Both of these lists are generally safe to use. If MS is using the SBL, it’s very likely they’re using the other two as well.
 

Related Posts

What causes Spamhaus CSS listings

Today’s Wednesday Question comes from Zaib F.

What causes the Spamhaus CSS listing in your experience other than Sender using multiple sets of IPs, to look as if they are a valid sender. Do you think a Spamtrap plays a role?

Read More

Questions about CAN SPAM.

In the US, the law governing the sending of commercial email is CAN SPAM. I’ve seen a number of questions about CAN SPAM recently.
One came from twitter, where someone was asking if just having an email address meant permission to send to it. Clearly, just being able to dig up an email address doesn’t imply permission to send marketing or commercial email to it. I can promise you April23@contact.wordtothewise.com did not sign up to receive information on increasing Facebook followers.
CAN SPAM doesn’t prohibit unsolicited email. All it says is that if you send unsolicited email you must do a few things.

Read More

dDOS spreads to the CBL

Spamhaus has mostly mitigated the dDOS against the Spamhaus website and mailserver, but now the CBL is under attack. They have been working to get that under protection as well, but it’s taking some time.
Right now there are no public channels for delisting from the CBL. The Spamhaus Blog will be updated as things change, and I’ll try and keep things updated here as well.
UPDATE: Cloudflare talks about the scope of the attack

Read More