SPF and MailScanner
P.G.M.Peters at utwente.nl
Fri Jan 30 10:09:15 GMT 2004
On Thu, 29 Jan 2004 18:37:47 +0000, you wrote:
>On Thu, 2004-01-29 at 18:17, hermit921 wrote:
>> I read that SPF (Sender Permitted From) is being incorporated into
>> spamassassin 2.70. Since the idea is to not accept (reject after HELO
>> step) any message that fails the SPF test, I conclude SPF can't be used by
>> MailScanner. It can be implemented in postfix, exim, sendmail, etc before
>> MailScanner sees the message. Is this a correct summary?
>SPF is just another means to help determine the likelihood of a message
>being spam or not. It is true that many sites may eventually want to
>use this to block mail, however this is not the only way to use it.
>SpamAssassin is likely to use it like they use rbls, as a trigger for a
>score. So you certainly could use it with SA through MailScanner,
>although this would not block the mail during the SMTP transaction (but
>this is the same decision you take if you use RBLs in SA or MS rather
>than your MTA.
>That said, if SPF gains widespread acceptance (AOL is testing at the
>moment I think, which is a good sign) and proves to be workable then
>using it at the MTA level may be considerably more effective than using
>RBL's in the MTA, with a much lower incidence of false positives (which
>will invariably be caused by bad system administration of the senders
Just read a good piece in NANAE about reasons why SPF will not going to
work. At least for a whole lot of people and (small) bussinesses.
Eventually you would have to include all IP-addresses in the list from
where your domain can be used to send e-mail. Or restrict the use (and
ease) of e-mail.
Peter Peters, senior netwerkbeheerder
Dienst Informatietechnologie, Bibliotheek en Educatie (ITBE)
Universiteit Twente, Postbus 217, 7500 AE Enschede
telefoon: 053 - 489 2301, fax: 053 - 489 2383, http://www.utwente.nl/civ
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