Thank you for contacting Aspose Support team.
In such case, where the attachment extension is not available and you want to determine if the attachment is an email message, please use the following code sample that determines if the content type of the attachment is that of an email message. Please try it at your end and let us know your feedback.
MailMessage myMsg = MailMessage.Load(“CompoundMessage.msg”);
int i = 0;
foreach (Attachment a in myMsg.Attachments)
That works great, thanks.
Thank you for sharing your feedback and please feel free to write to us in case you have any other query.