Email Balancer

For our users who want to switch from one ESP to another smoothly, without a deliverability issues, we offer a special product called Email Balancer. It allows to make ESP transition slowly, decreasing the sending volume on old ESP and increasing the volume on new ESP simultaneously, step by step, during several weeks.

How does it work

You change on your side host and port of your current ESP provider to the host and port of our Email Balancer, and as a first step we set 100% traffic to your current ESP. When you see it works, our deliverability specialists advise you about the transition path and volumes, and we set it up on our side so that every day more and more emails are sent thru UniOne and less and less email thru your previous ESP, with monitoring in process. And in several days all your traffic goes thru UniOne with maximum delivery rate.

Requirements & compatibility

For now, only standard SMTP protocol is supported. So if you are sending thru SMTP, you can benefit from Email Balancer. Just ask our sales team how to use it during the integration phase. We have tested it with the following providers:
  • - Mailgun SMTP
  • - Sendgrid SMTP


By default we offer to run it on our own hardware, so we will ask you for the credentials of your current provider to be able to route traffic between two SMTP connections. But it's also available in a docker image so you can run it on your side with a little consultation of our devops team.

Why businesses choose us?

UniOne is free and easy to start

Our users’ satisfaction is our primary value. Thus, we provide each newcomer with a 4-month free trial, including 6,000 monthly emails, to test our capabilities. Our round-the-clock customer care team is ready to assist you with any matters at each step of your journey with UniOne. When you feel ready to upgrade, choose any other tariff from the ones available or contact our sales manager to discuss a customized plan.