More than that, you should send the email 'To' one address, and CC (or BCC) to one or multiple email addresses.

Replacing ' with "" you will send emails to 'foo@gmail.combar@gmail.comkaboom@gmail.com' which I guess you can figure out is wrong :)

What you should do is to send the email 'To: one@email.address.here' and 'CC: to@one.address.here, the.second@one.here' and so on ...

Just have a look at MIME::Lite examples