When you load this application and it starts up, does it create the log file or do you create the log file at the beginning?
If the program creates the log file, then you should have a configuration in the file that you need to look at.
If you must create the file, are you root when you do this? Most logfiles on my system are root:root owner:group.
Try to find a config related to the application that will allow you to specify the log file.
Unless you have already done this, as root, try "chown root:mail mylogfile" and "chmod 660".
