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Re: [LUG] SPF and false positives

 

On Thu, 1 Apr 2010, Martijn Grooten wrote:

We were talking about SPF here a few months ago and since then I have
noticed that a few people post to the list from IP addresses that
don't match the SPF record of their domains. Usually the envelope-from
is an address on a personal domain or a webmail account, but the mail
is sent through an ISP. The list software doesn't block but adds a
Received-SPF: (soft)fail header.

Now whatever you do isn't my business, but because I have an interest
in SPF, I wonder if you get away with this: I know many spam filters
add a few points to the spam score for failed SPF, while some MTAs
even block these connections outright.

How about a polite (private) email to everyone who gets a soft-fail just to let them know?

And while I'm not a fan of SPF myself, but at least my published records seem to work:

  Received-SPF: pass (pi.a-squared.co.uk: domain of drogon.net designates
    195.10.225.68 as permitted sender) client-ip=195.10.225.68;
    envelope-from=gordon+dcglug@xxxxxxxxxx; helo=unicorn.drogon.net;

(I know they didn't for a while though!)

Gordon

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