This KB explains each keywords may appear in "Changes:" section.
NoChange: Nothing was changed by CMN.
ActiveMailDropdownProcessed: CMN detect the mail contains Dropdown (collapsible sections) and processed it to be compatible with Exchange.
ActiveMailEncryptedDbProcessed: CMN detect the mail contains Encrypted DB and processed it to be compatible with Exchange.
ActiveMailHotspotProcessed: CMN detect the mail contains hotspot (includes button, Text pop-up and so on) and processed it to be compatible with Exchange.
ActiveMailMissingFormFieldProcessed: CMN detect the mail contains MissingFormField (documents with no form field) and processed it to be compatible with Exchange.
ActiveMailRemovedExtraneousAttachment: CMN detect the mail contains extra attached plain-text renderings of active-mail content and removed it.
ActiveMailRemovedOnd: CMN fail to process the OND (*1) and had to remove it.
ActiveMailRichMarkupProcessed: CMN detect the mail contains Notes Rich Markup and processed it to be compatible with Exchange.
ActiveMailStoredFormProcessed: CMN detect the mail contains Stored Form and processed it to be compatible with Exchange.
HtmlInsertedMessageHelp: CMN had inserted help message in the head of the processed mail.
HtmlModified: CMN had modified the content in html format part to be compatible with all target clients.
HtmlModifiedDocLinks: CMN had modified the Document links in the Html format part to be compatible with Exchange.
HtmlRemovedInvitationTextRendering: CMN had removed some junk Invitation Text Rendering which will cause mess up to make it compatible with all outlook clients.
MeetingModifiedDocLinks: CMN had modified the Document links in the calendar part to be compatible with Exchange.
MessageRemovedExtraAttachments: CMN detect the mail contains extra ghost attachment and removed it.
MimeModified: Any change by CMN will be marked as MimeModified.
MimeModifiedCharSet: CMN had changed the charset for some parts of the message.
MimeModifiedSubject: CMN had some change on the subject part of the mail.
MimeModifiedText: CMN had some change on the text part of the mail.
(*1) OND: One Note Document - Lotus Notes Encapsulated Memo File
It is a file that contains part of an Active Mail message, but not enough information to use directly, NSF file is converted from OND.