Forward mail via PHP

Looking for a better solution to forward mail from an IMAP account via PHP to another account. Right now I am utilizing the built in imap functions (i.e. imap_fetchstructure, imap_fetchbody, imap_header among others) to get the individual parts and a MimeMessage class to rebuild the message. Once the message is rebuilt I change the "To:" and then send it on. The problem is that messages are rebuilt successfully about 95% of the time. Can anyone suggest a better way to do this? Can I not just login to the account get the entire message, change the "To:" and send it on it's way leaving the message structure in tact? If so does anyone know of any pre-existing classes to take a message as input, change the "TO:" and use the result of this to send it out? Thanks, -Bob