Yes, Signatures for Office 365 does not store or read any information from the email body. All it does is add an email signature.
When Signatures for Office 365 processes an email, it examines the message to decipher the sender’s and intended recipient’s details so it can apply the relevant signature as configured within the UI. It also scans the mail for common strings that represent a reply separator, so the signature can be inserted in the correct location.
Signatures for Office 365 does not actually ‘read’ the message in the traditional sense and the email content is not saved (persisted to disk) or available to Exclaimer personnel.
For more detailed information and for any security issues, please contact Exclaimer Sales.