Microsoft MXs changed over

Microsoft Send is a new mail client by Microsoft for iPhones and soon Windows Phone and Android phones. Send is designed to send quick, short messages to contacts. Instead of building a chat application build on a proprietary protocol, Send sends and receives its messages over email and uses your existing mailbox to handle the messages. What makes Send neat is that I can start a conversation within the app and when I get back to my computer, I can log into Outlook Web Access and continue the conversation.

 
Messages to and from the Send app do not utilize subjects lines.
 
Sending a message from my personal account with Office365 to my Word to the Wise account and the email looks like any other email I received except with the #Send on the subject line.

 
The message goes through the same outbound mail servers as if I sent it from Outlook or OWA, so emails pass SPF.
 

 
If you are signing with DKIM, the emails will be signed and authenticated.

 
(Office365 will sign emails with DKIM soon, it’s on the Office RoadMap.)
For an email to show up within the Send app, the subject contains #Send.
Microsoft has taken a unique approach to building a messaging app that utilizes existing SMTP infrastructure. If you’re sending to a tech savvy list, take a look at your logs to see how many recipients are using Microsoft Send and consider reaching out to them specifically using #Send.