When a user from O365 is sending an email with the classification “C3” the flag “$KeepPrivate=1” is added to the mail header and you cannot answer the mail because the mail is flagged like you change the settings in the Delivery Options to “Prevent copying”.

This issue can be solved by adding one of the following entries in the NOTES.INI of the server:


SMTP_NO_MAP_PERSONAL – if set to 1, do not map ‘Sensitivity: Personal’ header to $KeepPrivate=”1″

SMTP_NO_MAP_PRIVATE – if set to 1, do not map ‘Sensitivity: Private’ header to $KeepPrivate=”1″

SMTP_NO_MAP_COMPCONF – if set to 1, do not map ‘Sensitivity: Company-Confidential’ header to $KeepPrivate=”1″

Those settings are listed in an official KB entry:

https://support.hcl-software.com/csm?id=kb_article&sysparm_article=KB0080542