Difference between Sender ID and SPF?

am 23.06.2005 21:00:55 von michaeln

So... I was reading this article about how Microsoft intends to push their
own anti-spam mechanism on Hotmail users. They call it Sender ID:

http://www.techworld.com/security/news/index.cfm?newsid=3908

So, I went to the Microsoft site and looked up information on Sender ID but
it sounds like it's just SPF. They say that it's a combination between SPF
and their own "Caller ID", but I don't see where their part is included.

http://download.microsoft.com/download/9/c/f/9cf82def-4e0e-4 2f9-8629-bc5120043fef/senderid_overview.pdf

Here's what the "How it works" section is described:

The steps are:
1. The sender transmits an e-mail message to the receiver.
2. The receiver's mail server receives the e-mail.
3. The inbound server checks which domain claims to have sent the message,
and checks the DNS for the SPF record of that domain. The inbound server
determines if the sending server's IP address matches any of the IP
addresses that are published in the SPF record.
4. If the IP addresses match, the mail is authenticated. If the addresses
do not match, the mail fails authentication and receives a negative score.
These results are then be applied to existing anti-spam filtering policies
and
heuristics.

That sounds like SPF and only SPF to me. Could someone explain to me what
the difference between Sender ID and plain SPF is?

Michael

Re: Difference between Sender ID and SPF?

am 24.06.2005 04:07:02 von DFS

Michael wrote:

> That sounds like SPF and only SPF to me. Could someone explain to me what
> the difference between Sender ID and plain SPF is?

1) SPF is simple and Sender ID is complicated.

2) SPF wasn't invented by Microsoft.

3) SPF is freely usable; Sender-ID might be patent-encumbered.

Do you understand now why M$ pushes Sender-ID? :-)

I expect that MSN and Hotmail users will revolt 2-3 days after M$
turns this "feature" on, when all their friends' and relatives' emails
are junked.

Regards,

David.

Re: Difference between Sender ID and SPF?

am 24.06.2005 06:49:35 von michaeln

"David F. Skoll" wrote in message
news:EqGdnc5r7o1b9ybfRVn-ig@magma.ca...
> Michael wrote:
>
> > That sounds like SPF and only SPF to me. Could someone explain to me
what
> > the difference between Sender ID and plain SPF is?
>
> 1) SPF is simple and Sender ID is complicated.

It looks the exact same to me.

> 2) SPF wasn't invented by Microsoft.

As far as I can tell, neither was Sender ID....as it looks just like SPF!

> 3) SPF is freely usable; Sender-ID might be patent-encumbered.

Maybe...if there was something proprietary in Sender ID.

> Do you understand now why M$ pushes Sender-ID? :-)

Of course....

> I expect that MSN and Hotmail users will revolt 2-3 days after M$
> turns this "feature" on, when all their friends' and relatives' emails
> are junked.

I do too. But I'd expect that they would also feel that way if they
enforced SPF. Products are often not used in the way that they were
originally designed. You might design something to be used as a way for
users to bookmark certain things but find that users are adding THOUSANDS of
these bookmarks instead of the dozens that you planned for.

SPF is kind of the same way. I find that for my users, it's not best for
determining if something is spam, but rather best used to help determine if
an email is a forgery. It's usually not all that interesting if the SPF
records for briancarter.com don't match, but VERY interesting if the SPF
records for ebay.com or paypal.com don't match.

Anyway, if someone could tell me the technical differences between Sender ID
and SPF I'd love to hear them. I haven't been able to figure them out from
reading the overviews.

Michael

Re: Difference between Sender ID and SPF?

am 24.06.2005 08:55:35 von Peter Peters

On Thu, 23 Jun 2005 21:49:35 -0700, "Michael"
wrote:

>> > That sounds like SPF and only SPF to me. Could someone explain to me
>what
>> > the difference between Sender ID and plain SPF is?
>>
>> 1) SPF is simple and Sender ID is complicated.
>
>It looks the exact same to me.
>
>> 2) SPF wasn't invented by Microsoft.
>
>As far as I can tell, neither was Sender ID....as it looks just like SPF!
>
>> 3) SPF is freely usable; Sender-ID might be patent-encumbered.
>
>Maybe...if there was something proprietary in Sender ID.

Microsoft doesn't care whether there is prior art when they patent
something. They know they have more money then anybody who would want to
take them to court over it.

--
Peter Peters, senior netwerkbeheerder
Dienst Informatietechnologie, Bibliotheek en Educatie (ITBE)
Universiteit Twente

Re: Difference between Sender ID and SPF?

am 24.06.2005 15:14:08 von Sam

This is a MIME GnuPG-signed message. If you see this text, it means that
your E-mail or Usenet software does not support MIME signed messages.

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Michael writes:

> "David F. Skoll" wrote in message
> news:EqGdnc5r7o1b9ybfRVn-ig@magma.ca...
>> Michael wrote:
>>
>> > That sounds like SPF and only SPF to me. Could someone explain to me
> what
>> > the difference between Sender ID and plain SPF is?
>>
>> 1) SPF is simple and Sender ID is complicated.
>
> It looks the exact same to me.

XML glob looks like plain text to you?

>
>> 2) SPF wasn't invented by Microsoft.
>
> As far as I can tell, neither was Sender ID....as it looks just like SPF!

Sender ID is SPF + Microsoft-patented XML goo.

>> 3) SPF is freely usable; Sender-ID might be patent-encumbered.
>
> Maybe...if there was something proprietary in Sender ID.

Microsoft is on record as claiming unspecified patent rights on intellectual=

property in Sender ID. Investigating whether their claims would hold up is
not something that was in scope of the IETF WG, so they decided to forget
the whole thing.

>> I expect that MSN and Hotmail users will revolt 2-3 days after M$
>> turns this "feature" on, when all their friends' and relatives' emails
>> are junked.
>
> I do too. But I'd expect that they would also feel that way if they
> enforced SPF.

My interpretation of this latest development is that all MS will do is start=

checking SPF records. They're saying â=9CSender IDâ=9D, but readi=
ng between the
lines I believe they'll be reading SPF records in absence of Sender ID
stuff.

> Anyway, if someone could tell me the technical differences between Sender =
ID
> and SPF I'd love to hear them. I haven't been able to figure them out fro=
m
> reading the overviews.

Sender ID is basically XML goo for describing the same rules that SPF uses,
plus fallback to SPF if the XML goo does not exist.

Only a Microsoft-kind mentality could possibly come up with an idea of
putting an XML parser into the mail server.

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Re: Difference between Sender ID and SPF?

am 24.06.2005 20:58:26 von michaeln

Sam writes:
>Michael writes:

[snip]

>> It looks the exact same to me.
>
> XML glob looks like plain text to you?

Hmm...I didn't seem the XML stuff in the Sender ID overview. They just
describe it as looking up SPF records and seeing if they match...you know,
like many of us already do.

[snip]

>>> I expect that MSN and Hotmail users will revolt 2-3 days after M$
>>> turns this "feature" on, when all their friends' and relatives' emails
>>> are junked.
>>
>> I do too. But I'd expect that they would also feel that way if they
>> enforced SPF.
>
> My interpretation of this latest development is that all MS will do is
start
> checking SPF records. They're saying "Sender ID", but reading between the
> lines I believe they'll be reading SPF records in absence of Sender ID
> stuff.

Yes, that's what it sounds like to me too. Thanks for the clarification,
Sam.

[snip]

Michael

Re: Difference between Sender ID and SPF?

am 24.06.2005 22:59:57 von Sam

Re: Difference between Sender ID and SPF?

am 25.06.2005 09:13:05 von michaeln

"Sam" wrote in message

[snip]

> Try looking up a TXT record for "_ep.hotmail.com". You'll get a basic
> XML-bastardized version of the TXT record for hotmail.com. The basic idea
> is look for XML goo in _ep.domain.com, and if not found fall back to the
SPF
> record for domain.com.

Hmm....interesting. I wonder why this isn't described in the Sender ID
overview at the Microsoft site. Anyway, this makes perfect sense, thank
you.

> See also: http://xml.coverpages.org/draft-ietf-marid-core-01a.txt
>
> This is mostly a historical footnote.
>
> And, it's also S T U P I D.

The fact that Microsoft says nothing about it on their Sender ID site makes
me wonder if they've abandoned the idea....

Michael