We have recently moved from using POP3 to MS Graph for downloading email messages via email listener, and we are using the option to save the original email in .eml format; we are encountering an issue with specific emails where the sender has chosen the option to send email on  behalf of a different user ; for those specific cases, it looks like the email listener is confused about the real sender, which is not recognized, and the .eml file which is produced does not contain any attachment of the original email.

This did not happen when using the POP3 download, because at that time, the listener was correct when inspecting the sender, for those emails, and all of the .eml files produced were always containing all of the attachments of the original email

Is this a known bug for the MS Graph connection, and if so does anyone know when it will be fixed ?

Thanks

Regards