Part of the Pear package is a Mail.php file. Universal Email needs to load this file. It is located in the Pear Path. When you enter the Path to Pear, you must include a trailing slash. the path should be entered as:
/usr/sbin/sendmail/
Universal Email will automatically append Mail.php to the end of the path you enter:
/usr/sbin/sendmail/Mail.php
If you dont enter the trailing slash, the path becomes:
/usr/sbin/sendmailMail.php
which causses the error.