If you've recently changed your email address and no longer have access to the old email, and are unable to access your Simplifi Account, please follow the steps outlined in this Support Article: https://www.quicken.com/support/e-mail-change-request-submission
The Article provides a Form that can be submitted to request that your email address be changed for your Simplifi Account. Please note that the Form is Quicken-based, as your Quicken ID and Simplifi Username (email address) are one and the same. The form does require that proof of your identity be attached, so please be sure to grab a photo of your Driver's License or State Issued ID, or another form of acceptable proof, before submitting the Form. Once submitted, you'll see a pop-up success message.
Please note that this method should only be used if you no longer have access to your Simplifi Account. If you're able to sign in to your Account at myaccount.quicken.com, you can manually change your email address, in addition to your password and other personal information, without submitting the Email Change Request Form. Please click here for more details.