I have a Hotmail account I have been using for testing. I have been using this account to submit test messages to myself through my contact form. Whenever this form is used, the visitors comments are sent to me at my main account address, and a "thank you for contacting me" email is sent to the visitor. In all cases, I have recieved the comments submitted via the form, but if I use my Hotmail account in my test mails, I do not receive the "Thank you" message, and I get no bounced or message back from Hotmail.
The same has occured with users of my forums. If they attempt to register using a Hotmail account, then they recieve no email, and I get no failure reports. It just "silently fails". Using a "paid" account to register works as expected.
I assumed this should be done from the command line after connecting using ssh. I copied and pasted the command, substituting my own Hotmail address. The server did not return any error, but there was no message delivered to my Hotmail account, and no bounce either.
I read about similar problems on the phpBB support forums (http://www.phpbb.com/phpBB/viewtopic.php?t=211974), and it is reported there that "Sometimes yahoo, hotmail, and other free providers filter out mails from unknown domains or domains set up on servers with virtual hosting". I was hoping that this was a known issue, and that there would be a way round the problem.
As far as I can tell, the phpBB script correctly sets the 'Return-Path' header to "firstname.lastname@example.org", but the emails from my forum have "email@example.com" as the 'Return-Path'.