Mailenable SMTP service stops as soon as you try to start it. In event logs:
The MailEnable SMTP Connector service terminated unexpectedly.
Download Mailenable distributive of the same version from http://www.mailenable.com/download.asp
Launch it on the server and perform installation over broken one. Mail accounts, data will be saved. Moreover Mailenable performs backup during installation.
The most possible reason is broken Mailenable installation.