[Win10prof(64), Outlook-2016(32), Gpg4Win 3.1.10/ GpgOL 2.4.2]
Outlook receives a html mail, signed with valid S/Mime signature.
GpgOL verifies signature => working, green trusted sign, html body content is shown.
If Outlook-2016 is configured for receiving TXT-only in 'Trust center/Email security' some HTML mails are trunctated, html body is deleted and cannot be recovered, content is lost!
If S/Mime signed mail has been received earlier as html mail without OL conversion and Outlook's configuration has been changed to TXT-only afterwards, after re-opening those mail bodies are deleted/ trunctated too, empty content. Mail headers are still present.
It must be caused by GpgOL's interaction with OL's TXT conversion. If viewing same mail in webmail account by browser before downloading it to Outlook/GpgOL, everything is ok.
Maybe another related issue is sending S/Mime signed txt only mails:
Body content is deleted also in OL's 'sended objects'.
If indexing those mails for example with common 'Copernic Desktop search CDS' or 'MailStore', it is indexed twice:
- as empty mail, no content
- as .txt file namend 'GpgOL_MIME_structure.txt' with included but not readable S/Mime body.