SPF, Hotmail, and Yahoo mail

[Dave Smith]

Dave Smith wrote:
> Here's some more information on the subject. I thought I would include 
> the messages as they come from "mail" vs. Thunderbird.

Here's an interesting tidbit from a guy with the same problem as me:

"I started playing around with clients rather than concentrating on 
server setup, and I've had some interesting results. I can send to 
Hotmail without a problem using Outlook 2003, but no cigar with Mozilla 
Thunderbird. I haven't tested other email clients yet, but I think that 
this suggests that the headers the email clients add to an email also 
play a crucial role in determining if the mail gets through or not. This 
is BAD news because as a system admin there is generally very little you 
can do about this. I'll be interested to continue testing, especially 
with the user-agent and x-mailer headers."

Source (near the bottom): 
http://www.iis-aid.com/articles/iis_aid_news/are_hotmail_cutting_their_own_throat

Very strange.

--Dave