[fetchmail-users] "requires envelope option!"

[Anne W. <can...@go...>]

I'm now fetching my husband's mail, as well as my own (using fetchmail with 
cron, running as david), but I'm getting:

fetchmail: warning: multidrop for pop3.mailbox.co.uk requires envelope option!
fetchmail: warning: Do not ask for support if all mail goes to postmaster!

This never happens when I collect my mail (fetchmail with cron, running as 
anne).  Googling hasn't come up with anything useful.  What is this about?  
Thanks

Anne