Have You Been Blocked from Sending Email?

We help get your email list back in compliance and ready to send. 

Get Started Now at

Are you a current Synapp.io customer? Log in here to access existing lists. 

Synapp.io is an Atlanta technology startup innovating the email compliance and deliverability space. 


Email Assurance for Email Service Providers

Protect Your Reputation & Stop Firing Customers

We partner with ESPs to offer an industry standard deliverability and compliance monitoring toolset for the full life cycle of a customer. 

Before a new customer ever sends an email, we provide an email assurance report during the onboarding process. All existing customers are monitored on an ongoing basis, alerting you of any customers in danger of having issues.

Avoid ever having to fire a good sender because of a degrading list.

Download the Whitepaper


Email Assurance API

Easy to Integrate


Our API offers a simple way to check the deliverability of an email address. Quickly find out if a single email address is deliverable in realtime, or check the deliverability of a list of email addresses using the batch API. 

Email service providers can utilize the batch API to simplify and automate the onboarding, monitoring, and remediation of users. Start your free trial or contact us for more information.

Start a Free Trial