Works a treat. Unless you use mailing lists that aren’t careful to regenerate your message as to clearly come from their servers. Or any of your recipients fo

Works a treat. Unless you use mailing lists that aren’t careful to regenerate your message as to clearly come from their servers. Or any of your recipients forward their mail somewhere else and aren’t careful how they forward it. Or your recipients use a domain that mishandles SPF records. Or ... any number of other problems.