Know-How Exchange : E-Marketing

We currently have a email marketing tool that doesn't quite fit my need for a small program -- it does not allow me to cc' the account manager on the comms to their customer (well it does but they recieve it as the customer would not the traditional cc'). We plan to invite small groups of customers to yearly events. We want to be able to do so easily, but with our branding of course, and allow the user to reply to a specific POC. sounds simple but, I am looking for an online site, with free invitations, that also allows me to choose colors, add logo, etc. Any recommendations?