Hey guys!
Having the same issue over here. Hosted on dreamhost, CF7 has been working well for as long as I can remember, then just stopped sending emails a day or two ago when I was updating WP and the CF7 plugin. The email that it's supposed to be sent to us a gmail.com address (not a monkeynoodle.com address).
Any help you could give me on this would be great! I tried to configure a SMTP plugin, but could not find one that worked. Not sure what you mean by it being a 'mail server' issue.