When configuring an event, you have a lot of flexibility on who and how you would to be reminded. As part of this you can define the email reminder frequency.
Trackado allows you to set a default value for your email reminder frequency. You can configure this in the "Setting" menu under "Default Email Reminder Frequency" in the "Settings" menu.
The configured frequency will be used as the default value when creating a reminder.
Of course the frequency can be changed for each individual event reminder.