Our DOTS Email Validation product performs 5 major checks to validate the email address.  One of these checks, the SMTP check, requires our service to communicate with target mail servers. The variable response times from these target mail servers can impact the validation results.

To help manage this variable and return the most accurate results, we include the input field "Timeout", which allows you to set how long you are willing to wait for a real-time response from the mail server.  The longer you can wait, the more accurate our validation. 

If you would like a more in-depth explanation, check out our blog, Best Practices for DOTS Email Validaiton.