[Citadel Support] Email sent once, but keeps being received every 35-40 minutes

[chfriend]

I sent an email out to everyone in an organization that I am moving over to
Citadel using my charter.net email account through the charter.net SMTP
server last night.  I was the only one that is currently setup in Citadel,
the rest went to email addresses on another domain.  Since then the email
keeps being received every 30-40 minutes.  I tried sending an email using a
different mail server and a different email address and now that email is
replicating itself too.  I sent an email to my charter.net account and it is
not replicating, but I cannot for the life of me figure out what is going
on.  Any suggestions?

I've tried:  restarting Citadel, rebuilding the database, running IGAB,
checking to make sure there isn't something else binding to port 25.  Nada.