When you create a POP account to import emails into tickets, there is an option to configure the Import Frequency. This is the interval, in minutes, that SmarterTrack checks the POP account for new messages. By default, the import frequency is 2 minutes. You'll find mention of this in the POP section of the online help article for Departments
Because SmarterTrack 11.x is still in BETA, I'll assume you're on version 10.x or earlier and list those steps for finding this setting. Please keep in mind though, that the location of this setting differs in version 11.x. To find the Import Frequency setting, log in as the System Admin and click on the Settings icon. Expand the System Settings and Organization folders in the navigation pane. Click on Departments. Edit the department that has the POP account configured and click on the POP tab. Modify the Import Frequency setting as desired. Be sure to click Save in the content pane toolbar.
I hope this helps!