Configuring Sender Address Match

After you have provisioned an Exchange Online (Inline Mode) Authorized Account, you can specify the header addresses used for matching the approved or blocked sender lists in the ATP policy.

  • Envelope address: address used by the mail transfer agent to route and deliver an email message

  • Message header address: address specified by the "From" header of an email message

Both addresses are selected by default and the selection of Envelope address cannot be canceled.

  1. Go to Administration > Global Settings > Inline Protection Settings for Exchange Online.
  2. Click Inbound Protection.
  3. Under Sender Address Match, select or clear Message header address.