If you are using a POP3 email account with Outlook and have the option
set to leave a copy of the emails on the email server, then I would
login to the web based email server if you have that option and delete
the email from there, so it no longer exists on the email server and
outlook will no longer see it on the email server so it will not
download it. Is the issue only happening on this one deleted email or
any deleted emails?