That is the intended/desired functionality. It means that 130 visitors visited your website after the Maintenance Mode Countdown Timer completed/reached 0. The reason this is desired is lets say you completely forget that your site is in Maintenance Mode. It would be very hard for this mistake to turn into a catastrophy since you are sent an email reminder every time a new visitor visits your website. The assumption made is this: if you set the Maintenance Mode Countdown Timer for 6 hours then you plan on putting your site in Maintenance Mode for 6 hours and no longer then that. If you need to extend that Maintenance Mode time you would extend the Countdown Timer time in the Maintenance Mode options. The most important aspect of this reminder email is to make sure a catastrophic mistake is not made – your website is in Maintenance Mode when you think it is actually Live.
http://forum.ait-pro.com/forums/topic/maintenance-mode-guide-read-me-first/
Send Email Reminder when Maintenance Mode Countdown Timer has completed:
Check this checkbox to enable the javascript Countdown Timer to send you an email reminder when the Countdown Timer reaches 0 / is completed. More importantly when this option is selected you will receive another email reminder each time a visitor visits your website.