Mailing List CGatePro@mail.stalker.com Message #102159
From: Jeff Wark <jwark@tbaytel.net>
Subject: Re: Blackberrys and SPF
Date: Thu, 16 Jun 2011 12:43:00 -0400
To: CommuniGate Pro Discussions <CGatePro@mail.stalker.com>
On 6/16/2011 3:20 AM, Fred Zwarts (KVI) wrote:
"Lyle Giese"  wrote in message news:list-67692281@mail.stalker.com...

On 06/15/11 12:08, Jeff Wark wrote:
We currently have our server set to enable SPF checks. This causes a
problem every few months where an email is rejected due to being
forwarded from somewhere. This is a small inconvenience and can normally
be worked around.

The big [repeating] problem is with Blackberry's. People using their own
email domain [with no SPF], but the blackberry does some magic and gives
the email an email address like <some strange username
formula>@srs.bis6.us.blackberry.com. This often causes a rejection of
the email that we cannot easily fix. The blackberry SPF record itself
seems a bit extreme:
$ host -t txt srs.bis6.us.blackberry.com
srs.bis6.us.blackberry.com descriptive text "v=spf1 ip4:206.51.26.0/24
ip4:193.109.81.0/24 ip4:204.187.87.0/24 ip4:216.9.240.0/20
ip4:206.53.144.0/20 ip4:67.223.64.0/19 ip4:68.171.224.0/19
ip4:74.82.64.0/19 ip4:178.239.80.0/20 -all"


Does anyone know of a way to not reject those specific blackberry emails
based on SPF records?

I just wish they would "~all". I like the intent of SPF records and like
to follow them, but "-all" always seems like a mistake to me unless you
are someone running your own mailserver and understand what limitations
you are imposing on yourself.

-Jeff


I think you are asking the wrong question about SPF.

How many bad emails am I rejecting using SPF?  When I asked that question and found I could not measure the % rejected since I was dumping less than one per week, was it worth checking SPF? unfortunately, no.

As you are finding the 'collateral damage' is far greater than any good SPF is doing for you.

Lyle Giese
LCR Computer Services, Inc.

I our case the SPF check currently rejects about 30 messages per hour, with 0% collateral damage.
So, the good is infinitely greater that the damage.


Just checking for yesterday and there were 15,000-16,000 SPF rejections based on source address.
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