Paul Maye, our Network Administrator at Infacta discovered an interesting filtering algorithm used by Hotmail while doing some testing for a customer who was having problems getting email delivered to his Hotmail recipients.
When you send an email to a Hotmail recipient from a Hotmail email address, but routed through a third-party SMTP server, the message is considered *Dangerous* and there is no option for the recipient to mark it as “safe”. Even if the recipient adds the sender to their safe list, future messages from them will still be marked “This message may be dangerous”.
I suppose Hotmail wonders why anyone with a Hotmail address wouldn’t send their email through Hotmail’s own mail server.
So if you are going to use a third-party SMTP server to send your messages to Hotmail recpients, you might want to send it using a domain email address instead of your own Hotmail address.
