If your mail is hosted with Microsoft on Office365/Hosted Exchange, these settings should work in Mail Merge as long as you enter the correct account information:
SMTP server = smtp.office365.com SMTP login User name = the email address of the account you want to use SMTP Login Password = the password for the email address of the account you want to use From Email Address = the email address of the account you want to use Port = 587 Use SSL/TLS = checked
Please note that this information is provided as a courtesy based on our own testing on accounts we manage. If these settings do not work for you, you will need to contact your e-mail administrator or IT support provider for additional assistance.