Home / Blogs

Microsoft’s Offer to Buy Yahoo: An Anti-Spam Point of View

Last Friday, Microsoft made an unsolicited offer to buy Yahoo for $31 per share, representing over a 50% premium from Yahoo’s then-share price.

As an employee working for Microsoft in Exchange Hosted Services (i.e. spam filtering), I’d like to comment on this buyout offer. Leaving aside the question of whether or not this is a good deal for shareholders and what Microsoft’s true motivations are for buying Yahoo (namely, to become the number 2 player in the search market), I’d like to look at it from an anti-spam point of view. What are some of the things that the two companies can do to work together from an email delivery vantage? Here are some of the things that I can see:

Spam filtering algorithms - Hotmail’s Smartscreen technology could use some improvements, I think most people in Hotmail would be open to improvement in the product. I’d like to see Microsoft and Yahoo get together and combine the best of Smartscreen and Yahoo filtering to improve the product.

DKIM implementation - As far as I know, there isn’t a major movement within Microsoft to do DKIM. Not that anyone was opposed to it, but there was a big push to do SenderID and to support that. Now that Microsoft is acquiring the guys who invented DomainKeys, the predecessor to DKIM, it makes sense to do it now. Gmail does both DKIM and SPF, now perhaps Hotmail can do both as well.

Will Yahoo now do SPF? - Yahoo so far has resisted publishing SPF records. Microsoft is very big on getting customers to publish SPF. Maybe now we Yahoo will do it.

I wouldn’t expect convergence to occur very quickly. Yahoo runs on Unix or BSD and it will take a very long time to switch over to Windows. Still, the opportunities for anti-spam collaboration are promising.

By Terry Zink, Program Manager

Filed Under


Suresh Ramasubramanian  –  Feb 4, 2008 10:16 AM

Yahoo has shown remarkably good sense not touching SPF (or senderid) with a bargepole. Being forced into doing it would be a disservice to yahoo users.

Larry Seltzer  –  Feb 4, 2008 11:26 AM

If they continue to support DKIM what’s the downside to publishing SPF records?

Carl Byington  –  Feb 5, 2008 6:33 AM

Just a waste of time and effort.

Hotmail currently publishes ~all form

hotmail.com. 3600   IN     TXT   “v=spf1 include:spf-a.hotmail.com include:spf-b.hotmail.com include:spf-c.hotmail.com include:spf-d.hotmail.com ~all”

So if we ask “should ip address a.b.c.d be sending email from the hotmail.com domain”, hotmail explicitly answers “we don’t know”. How is that different from what you would know if there were no spf record?

Comment Title:

  Notify me of follow-up comments

We encourage you to post comments and engage in discussions that advance this post through relevant opinion, anecdotes, links and data. If you see a comment that you believe is irrelevant or inappropriate, you can report it using the link at the end of each comment. Views expressed in the comments do not represent those of CircleID. For more information on our comment policy, see Codes of Conduct.

CircleID Newsletter The Weekly Wrap

More and more professionals are choosing to publish critical posts on CircleID from all corners of the Internet industry. If you find it hard to keep up daily, consider subscribing to our weekly digest. We will provide you a convenient summary report once a week sent directly to your inbox. It's a quick and easy read.

I make a point of reading CircleID. There is no getting around the utility of knowing what thoughtful people are thinking and saying about our industry.

Co-designer of the TCP/IP Protocols & the Architecture of the Internet



New TLDs

Sponsored byRadix


Sponsored byVerisign

IPv4 Markets

Sponsored byIPv4.Global

Domain Names

Sponsored byVerisign

Brand Protection

Sponsored byCSC

Threat Intelligence

Sponsored byWhoisXML API


Sponsored byDNIB.com