we are using Go's net/mail to parse message headers. it can parse addresses,
and properly decodes email addresses with double quotes (e.g. " "@example.com).
however, it gives us an address without the double quotes in the localpart,
effectively an invalid address. we now have a workaround to parse such
not-quite-addresses.
for issue #199 reported by gene-hightower, thanks for reporting!
016fde8d78