you will want to record both success and failure.
since your script is timing out, it is not getting to all addresses, you want to know which addresses it has been able to get to, those will be stored by the success and failure, emails not in the log are the addresses that the script did not get to before the time out.
The inability to save is a bug when using the Create Table for me option. you can use the following SQL to create the table:
CREATE TABLE `email_log` (
`EmailID` int(11) NOT NULL AUTO_INCREMENT,
`EmailTo` varchar(250) DEFAULT NULL,
`EmailFrom` varchar(250) DEFAULT NULL,
`EmailSubject` varchar(250) DEFAULT NULL,
`EmailStatus` varchar(50) DEFAULT NULL,
`EmailDate` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`EmailID`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1
then use the current email bindings in the log to set the logging settings.