Rezora is a multichannel digital marketing platform for large sales and marketing organizations. They enable collaborative marketing across complementary marketing channels, help expand digital marketing reach by unlocking sales teams’ marketing potential, and provide personalized content and data solutions specific to your industry and audience.

Rezora specializes in companies that have a large, distributed sales force where marketing wants to communicate and run campaigns with key prospects on behalf of their sales agents. This allows organizations to deliver a consistent message to potential clients through a variety of marketing channels, with email being a core component of their overall offering.


Rezora provides a multi-tiered email marketing platform for large sales and marketing organizations.


Boulder, CO


Solutions Used

SendGrid API and SMTP

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Rezora launched in 2009 as part of the TechStars accelerator along with SendGrid. To power their platform, Rezora needed an email delivery solution that could effectively plug into their software, scale up as the company grew, and eliminate the need for them to manage their email system. As a startup with a small technical team of two engineers, they needed a tool that would enable them to 100% focus on building their core product, not on email delivery.

At the time, SendGrid was still building out their platform so they went with another provider that provided an API on which to build their application. However, in time, they found that they needed a provider that was focused on providing OEM solutions (backend email infrastructure and services that can be whitelabeled on behalf of a client who offers email as a service) rather than a frontend WYSIWYG provider designed for sending broadcast marketing email.



As SendGrid continued to build their product, Rezora found that SendGrid was very focused on solutions that supported a cloud-based backend email infrastructure centered on the successful delivery of email. Furthermore, they employed a staff with core email deliverability expertise that would alleviate the need for day-to-day email management by the Rezora team. Coupled with SendGrid’s affordable pricing model and scalability, they determined that SendGrid was the right service needed to expand Rezora’s platform for the long term.



Integrating with the SendGrid platform was simple. First, they use the SMTP API to programmatically add categories to their emails so they can provide data and analytics back to their clients. Rezora builds statistics dashboards for their customers and having the ability to tag all outgoing mail with SendGrid category headers is key to handling and processing the data they get back from the Event Webhook.

Next, they use the Event Notification Webhook to integrate the SendGrid data into their own system—a step that enables them to send email response data back to their clients. Using a simple JSON format set of object notations, all the raw response data is packaged, standardized, and pushed to Rezora in real time. Rezora then parses the data, transfers it to their database, and repackages it using their own business intelligence into a user-friendly format for their clients.

Finally, they use the Web API to tie-in data and create a custom interface for their internal reporting tools. This provides their customer support staff with the business intelligence to perform key tasks like managing global unsubscribe lists.

Rezora now sends approximately four million emails per month (over 10x their original email volume after TechStars) on behalf of their clients, which include real estate, pharmaceutical, non-profit, financial services, and hospitality companies. They also work with franchises, national associations, multi-level marketing firms, and consultancies.


Our entire application sits on top of SendGrid and they are doing an exceptional job of managing our email infrastructure and delivery needs. Since switching to SendGrid, performance has been outstanding, plus they have an entire team dedicated to email; expertise we couldn’t afford to staff in our organization. With SendGrid, we can focus on our core product because we know that once we hand it off to SendGrid, the process will be flawless and our emails will get delivered.

Paul Reinarz CEO

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