Are Hotmail cutting their own throat
UPDATE: Email clients play a role too
While reading back through this article I noticed that it was totally server centric, with no consideration of what an individual email client might be doing to effect an emails deliverability to Hotmail. Email clients are responsible for adding header information which is widely used for aiding in anti spam purposes.
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.
This one should not be a hard one to come to. If people are not able to be confident that mail sent to Hotmail will get there, then why use their services? Especially when there are so many other players in the field. I have now configured rules for this website that ban the use of Hotmail addresses during signup, and have configured my email server to send a message to any of my users sending to a Hotmail account informing them that their email is unlikely to get through. I realise that me banning Hotmail is not going to make any difference, but get 1000, then 10,000 the 100,000 other webmasters just like me doing the same thing and you really have to ask yourself. Are Hotmail cutting their own throat?