
Explanation:
https://docs.microsoft.com/en-us/office365/securitycompliance/go-to-the-securitycompliance- センター
https://docs.microsoft.com/en-us/exchange/security-and-compliance/mail-flow-rules/disclaimers- signatures-footers-or-headers
https://www.itprotoday.com/email-and-calendaring/configure-email-disclaimer-exchange-server-
2016
https://docs.microsoft.com/en-us/office365/troubleshoot/administration/switch-channel-for-office-
365