Does this help?
MVP - Exchange
"Protecting the world from PSTs and brick backups!"
"Bryce" <firstname.lastname@example.org> wrote in message
> Task 'Microsoft Exchange Server - Sending' reported error (0x80040610) :
> 'Unknown Error 0x80040610'
> This person sent an email to a distribution group we have set up. It seems
> that everyone got it but the error came to her like that.
> Any ideas?