Can anyone recommend a good mailing list software?

I was intending to use mailman but my webhost cannot get it working properly with CPanel.

My need is to provide a simple internal commmunications system for my small 'team' to email all others by sending only one message. It needs to be secure enough to prevent public access because a lot of the information will be commercially confidential.

(I don't mean the Gossamer list type of software for sending out to multiple recipients otherwise I would use it)

Thanks in advance.