Why does the Inbox rate get worse if I test the same message multiple times?

The GlockApps seed list represents a cold audience meaning that GlockApps doesn’t interact with the messages sent to the seed list. As prior user engagement may be taken into account by different ISPs, it is not recommended to run multiple tests for the same message within a short time as spam filters can track this activity and mark your message as spam. It is advised to run the tests with a reasonable interval of 15-20 minutes to receive as equitable results as possible.