The Risks of Using Multiple Email Providers

22 March 2017 - Sharon Beilis

When you’re trying to increase email deliverability rates, considering to use multiple email service providers can make things more efficient. Before taking the road less traveled, though, you need to be aware of some inherent risks of spreading data across multiple providers.

Think about these risks of using multiple email providers for a given campaign:

 1. Sending Duplicate Emails

When you’re not proactively scrubbing duplicates off your lists, using multiple providers may cause recipients to receive multiple messages from the same campaign. This can trigger an unsubscribe or spam complaint.


Make sure to remove all hard bounces immediately and check your list segments for duplicate email addresses that may have come in from different sources or at different times. The easiest way to do this is to make sure you have a centralized hub of all email addresses as a master list and that all segments are created from the scrubbed master.

2. Sending Emails to Unsubscribed Users

When a customer unsubscribes from receiving emails from your company, it is your responsibility to make sure their unsubscribe request is fulfilled through all providers.


This can be easy to miss if the customer entered their email address for two or more different brand sites, signed up for a newsletter, or shared their email for any other reason. Like with the risk of duplicate messages, having a centralized hub for all your email data can help ensure you’re not affecting email deliverability by sending emails to people who have unsubscribed and might report your emails as spam.

3. Lower Cost-Efficiency

Since every email service provider charges different rates (and provides different results), some of your email sends will generate more revenue and be more profitable than others. You need to consider which brands or types of emails are providing the most value and rank your ESPs accordingly.


This can give you a better idea of how much it costs to manage certain campaigns and calculate an accurate ROI. There may be higher operational costs involved with using multiple email service providers so you need to review budgets and expenses regularly to determine what is a good match for your company.

4. Inaccurate KPIs

When you’re drilling down into email metrics to review open rates, click-through rate, and other data, you may not be able to do an “apples to apples” comparison between email service providers if you haven’t streamlined deliverability across the board.

If you’re not cleaning out your lists of unsubscribes, accounting for hard bounces, and accounting for inaccuracies in open rates, you may be working with inaccurate KPIs when you take the average of metrics across several ESPs.


Keep this in mind especially when sending out larger batches of emails at a time — your numbers may be all over the place among different ESPs, so even an average may not be a good indicator of success or failure.


Using multiple email service providers can offer many benefits, but you need to be extra vigilant about cleaning out your email lists and have a system in place to manage metrics and analytics accurately.