Codeigniter sending blank emails when more then one email is sent in a single request

Have you tried clearing before the second send to reset everything?
http://www.codeigniter.com/user_guide/li...ail::clear

Or perhaps try using php's native mail() and see if it still happens. That would at least rule out a CI issue, and perhaps give more clues?

That might not be much help as it seems you are doing everything perfectly well, sorry.

Paul.