Seeing as the error is related to the post filter is there a way to temporarily disable the post filter and test if she receives email?
relay=mailpostfilter, delay=0.56, delays=0.08/0.06/0/0.42, dsn=4.3.0, status=deferred (temporary failure. Command output: Failed to set recipient: , code=-1, original code -1)
It seems that I would edit /etc/postfix/master.cf but what? just hash out the post filter altogether?
uninstall and reinstall the email anti spam etc?