version: STSv1
mode: [enforce|testing|none] # 1. Decide your mode.
mx: mx1.your_domain.tld      # 2. Add your primary mailserver hostname (see MX records in your DNS)
mx: mx2.your_domain.tld      # 3. If you have secondary mailservers, add one line for each.
                             #    In case all servers share the same subdomain, you may also use wildcards like *.mail.protection.outlook.com
max_age: 1209600             # 4. Depending on your mode above, 1209600 seconds = 2 weeks might be a good value.
                             # 5. Remove all the comments (if that wasn't obvious to you).