ok, lists of addresses need to be a list in the call to sendmail(),

but when MIME encoding the message (headers), the To: line must be a string. And there must be a space after the commas.

(previously, this resulted in only the first recipient getting the message)

![improper_docs](https://f.cloud.github.com/assets/132518/39405/7ea9811e-5527-11e2-9d36-2f331bdeaeb9.jpg)