Question regarding SPF

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Question regarding SPF

Kammen van, Marco, Springer SBM NL

Hi All,

 

We recently took over a company that used SPF.

Because our e-mail infra is way more complicated than theirs and we have tons of external parties who send mails using our domains, we decided long ago not to use SPF.

 

Now they say that %5 of their mailings don’t arrive at customers anymore, and say this is because we removed their SPF records..

I’m no expert on SPF but as far as I understand it only checks if a sender is ‘allowed’ to send using that domain, so no relation what so ever on dropping mail from parties that don’t use SPF…
Or am I missing something?

 

Thanks & Regards,

 

Marco van Kammen
Springer Science+Business Media
System Manager & Postmaster

van Godewijckstraat 30 | 3311 GX
Office Number: 05E21
Dordrecht
| The Netherlands

  

tel 

 +31(78)6576446

fax 

 +31(78)6576302

www.springeronline.com
www.springer.com

 

 

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Re: Question regarding SPF

Paweł Leśniak
W dniu 2009-04-17 08:50, Kammen van, Marco, Springer SBM NL pisze:

Hi All,

 

We recently took over a company that used SPF.

Because our e-mail infra is way more complicated than theirs and we have tons of external parties who send mails using our domains, we decided long ago not to use SPF.

 

Now they say that %5 of their mailings don’t arrive at customers anymore, and say this is because we removed their SPF records..

I’m no expert on SPF but as far as I understand it only checks if a sender is ‘allowed’ to send using that domain, so no relation what so ever on dropping mail from parties that don’t use SPF…
Or am I missing something?

 

It might be their IP's are on some blacklist and while they've had SPF record their emails were not checked in (some) RBLs. There's no such rule, but one can configure something like that.
Also it can be related to mail content, or amount of emails per piece of time to the same server. You could think of SPF usage like some kind of whitelisting, but that's dependent on one's configuration at client's side (the side which uses SPF record, not the one provides it).

For sure there's no straightforward relation between not using SPF and emails being rejected.

Maybe you've got some more information from logs why emails are being rejected?

Pawel Lesniak

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Re: Question regarding SPF

martijn.list
In reply to this post by Kammen van, Marco, Springer SBM NL
> I’m no expert on SPF but as far as I understand it only checks if a
> sender is ‘allowed’ to send using that domain, so no relation what so
> ever on dropping mail from parties that don’t use SPF…
> Or am I missing something?

A lot of statistics are used to filter out spam so it wouldn't surprise
me if having SPF records helps to lower your change of bein filtered.

first hit on the search "spf spam filtering"

http://www.wilsonweb.com/wmtp8/spf_howto.htm

Martijn Brinkers

--
Djigzo open source email encryption www.djigzo.com
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Re: Question regarding SPF

Roel Wagenaar-2
"martijn.list" <[hidden email]> wrote:

> > I’m no expert on SPF but as far as I understand it only checks if a
> > sender is ‘allowed’ to send using that domain, so no relation what so
> > ever on dropping mail from parties that don’t use SPF… Or am I missing
> > something?
>
> A lot of statistics are used to filter out spam so it wouldn't surprise me
> if having SPF records helps to lower your change of bein filtered.
>
> first hit on the search "spf spam filtering"
>
> http://www.wilsonweb.com/wmtp8/spf_howto.htm
>
> Martijn Brinkers
>
The home-page of OpenSPF is here:

http://www.openspf.org/

--
Roel Wagenaar,
Timmerman-aannemer,
Tel.: 0513-789900.

If we aren't supposed to eat amimals, why are they made with meat?
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Re: Question regarding SPF

mouss-4
In reply to this post by Kammen van, Marco, Springer SBM NL
Kammen van, Marco, Springer SBM NL a écrit :

> Hi All,
>
>  
>
> We recently took over a company that used SPF.
>
> Because our e-mail infra is way more complicated than theirs and we have
> tons of external parties who send mails using our domains, we decided
> long ago not to use SPF.
>
>  
>
> Now they say that %5 of their mailings don’t arrive at customers
> anymore, and say this is because we removed their SPF records..
>

it may be simply because their mail is getting out from "new" IPs. you
can do a test by setting up SPF and trying...

in short, if the IPs they used to send from have acquired some
reputation, then sending via new IPs will lose that reputation.

> I’m no expert on SPF but as far as I understand it only checks if a
> sender is ‘allowed’ to send using that domain, so no relation what so
> ever on dropping mail from parties that don’t use SPF…

in theory, yes. but...

> Or am I missing something?
>