Can you please check your Outlook settings. Our server is receiving commands stating that if the email has been seen to place it into Trash. Also check your Outlook trash folder for any of the missing emails. I've reset the flag on your account to keep emails if the email client requests to delete it for now. Let me know if you can locate the emails in Outlook.
check the "recover deleted items" in the webmail and see if Outlook has anything similar to it. If its no longer on the webmail, Comcast would be unable to restore the emails.