I personally love the Airmail for Mac OS X application, but if there is something that I hate is when it doesn't work automatically as you expect it. A week ago I was trying to set up my college account of Microsoft Office 365 and was really quite frustrating, primarily because Microsoft does not provide enough third-party information and the Airmail support page is very widespread and insufficient and not me was helpful for anything. Fortunately, I was able to configure it successfully.
Let me help you with the configuration in three easy steps:
1. Log in to your account from Outlook, Hotmail or Office 365.
Go to the Outlook section and select the small gear (⚙) side.
Server name: smtp.office365.com Port: 587 Encryption method: TLS
Server name: outlook.office365.com Port: 993 Encryption method: SSL
Server name: outlook.office365.com Port: 995 Encryption method: SSL
3. Test information: once you have the data from the server, the port and the encryption placed in their respective place, remember to Test IMAP and SMTP Test to both buttons to make sure that everything is set up properly. You will receive a message saying that it was configured successfully, or that there was an error. If you had an error, check that you entered the data correctly.