Bah!
Silly vodafone is replying to any email sent to an @clear.net.nz email address with a reply that simply says
"This mailbox is closed"
Cant they just close the account and return the proper SMTP error code?
A customer's ticketing system now has several thousand tickets of back and forth replies of
Your ticket number is xxx
This mail box is closed
Your ticket number is xxy
This mailbox is closed
After a billing run attempted to send some statements to customers with @clear email addresses.