cforms email problem

I’m using the wonderful cforms plugin. It was working smoothly, but when I switched servers and the email started acting out. The form would submit, but no email would be sent. I disabled ajax, changed the “from’ address, and the emails are sent, but not to every email included in the admin list, which I separated with commas. Sometimes I get cc’ed on the messages, but more often I don’t. It would be simpler for me if it was all or nothing, but its some, which is irritating. Has anyone run into this kind of email flakey-ness and found a fix? Trouble-shooting pointers anyone? I’m at a loss. Thanks.