Please make sure you are using the GMail 2-Step Verification https://www.elkproducts.com/email-security-settings-using-app-passwords-for-gmail-and-yahoo-with-the-m1xep/ and under the M1XEP Setup, Email Tab the Password will be the 16 digit passcode provided by GMail. The M1XEP should also be running the 2.0.51 Firmware Update.