To avoid failing SPF, you would need to either (1) add all mail servers you might send through to the SPF config for the domain, or (2) use a much weaker SPF config that doesn't fail other mail servers. Option (2) makes SPF not very useful IMO, which is why it's much easier if users always authenticate through the mail server for the domain, or a short list of other mail servers.
There is actually a third option that allows for inheritance of SPF records, e.g. within your domain's SPF records refer to another domains SPF, but I haven't played with that yet. It could mitigate the problems with option 2 significantly if ISPs adopted SPF, and would make setup for the rest of us much easier since we wouldn't have to reference all of their mail servers, just their SPF. However, even with that option 2 loses a bit due to the possibility of spammers, zombies, etc. on the ISPs network who could forge your domains' addresses and pass SPF. Darin. ----- Original Message ----- From: "Martin Schaible" <[EMAIL PROTECTED]> To: "Darin Cox" <[EMAIL PROTECTED]> Sent: Tuesday, August 10, 2004 9:40 AM Subject: Re: [IMail Forum] SPF records Hi, Basically i understood this spf thing. What happens if: - I'm travelling in the usa. I use a free ISP service to stay connected to the world. To send mails, often the SMTP Server of the ISP must be used. But I'm using my regular email address as the sender. I think, that this spf record will avoid situations like that. Is this true? ==================================== Am Dienstag, 10. August 2004 um 15:01 schrieben Sie: > Yep, one for every domain, virtual or otherwise. > Darin. > ----- Original Message ----- > From: "Martin Schaible" <[EMAIL PROTECTED]> > To: "Mike Biddle" <[EMAIL PROTECTED]> > Sent: Tuesday, August 10, 2004 8:45 AM > Subject: Re: [IMail Forum] SPF records > Hi, > I have a question about this thread: do i have to create an SPF Record for > every host on > my mail server? > We're running one IP-host and tons of virtual hosts. > ==================================== > Am Dienstag, 10. August 2004 um 04:28 schrieben Sie: >> Has everyone heard about this? >> http://spf.pobox.com/wizard.html?mydomain=ipswitch.com >> Definately requires some thought.... >> To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html >> List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ >> Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/ > ==================================== ==================================== -- Mit freundlichen Gr�ssen ==================================== Merlin Consulting Martin Schaible Bahnhofstrasse 27 CH-8702 Zollikon Phone: +41 1 391 30 00 Fax: +41 1 391 32 49 Mail: mailto:[EMAIL PROTECTED] URL: http://www.merlinconsulting.ch Support: http://support.merlinconsulting.ch GPS: N47 20.235 E8 34.226 ==================================== To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/ To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
