Below are the steps required for you to setup your V8 site to use mail server Office 365 :
1. Login to your V8 administration and go to : Advanced Settings > Software Configuration.
2. Click Site Details.
3. Locate the following configs and set value below for each :
xemailsystem : smtp.office365.com
xemailsmtpport : 25
xemailsmtpusessl : Yes
xemailsmtpconnectiontimeout : 60
xemailusername : [enter your mail authentication username or your full Office 365 email address]
xemailpassword : [enter your mail authentication password or your Office 365 email password]
4. Click Continue.