Why Switching ESPs Won’t Save Your Email Program?

I recently joined Guy Hanson and Danielle Gallant on Validity’s “Email After Hours” podcast to discuss how senders should evaluate ESPs, why deliverability rankings can be misleading, and what really happens when you migrate between platforms.

The myth of the “best ESP for deliverability”

You’ve probably seen reports ranking ESPs by average deliverability. One platform supposedly has excellent deliverability, while another performs poorly.

I’m skeptical of these comparisons.

Many of these tests use relatively small seed lists rather than real subscribers. The same message is sent through several platforms to addresses at Gmail, Yahoo, Outlook, etc., and the researchers measure whether those emails reach the inbox or spam folder.

But seed addresses aren’t real subscribers. They don’t behave like real people, and mailbox providers use engagement and many other signals to decide where messages land.

You can’t conclude that HubSpot, Brevo, or another ESP has good or bad deliverability based on a test like this.

They can all be great platforms. A lot depends on how you use them.

 See more  in the article Can we compare email platforms?

Who is responsible for your deliverability?

When you buy a subscription for an email platform, you interact with its interface, segmentation capabilities, automation, reporting, AI features, and other tools.

But an email delivery infrastructure also operates behind the scenes. For most marketers, that aspect is effectively a black box.

The ESP has important responsibilities. These may include maintaining the quality and reputation of shared IP pools, supporting SPF and DKIM authentication, providing a meaningful onboarding process, having an extensive knowledge base, and making deliverability expertise available to customers.

Platforms also differ significantly. Some provide shared domains for tracking and image hosting, while others let customers use their own subdomains. Some offer more visibility and control over throttling and other aspects of email delivery.

But the sender also has responsibilities
Many email marketers are jacks of all trades, handling multiple aspects of digital marketing, so they expect the platform to handle every part of their email marketing success. They do not understand that email behaves differently.

Senders need to maintain list quality, configure the DNS records their ESP provides, implement and monitor DMARC, understand subscriber engagement, and follow best practices.

You can have an excellent email platform and still have terrible deliverability.

Switching ESPs can improve deliverability, but perhaps not for the reason you think…
One of the most persistent email marketing myths is that switching ESPs will magically fix deliverability problems. Many email marketers point to that option exactly when they have deliverability issues. They want to switch the platform.

Sometimes deliverability does improve after a migration. But that doesn’t necessarily mean the new platform has better deliverability.

Think about what happens during a well-planned migration: The sender cleans up and migrates data. Authentication is reviewed. Infrastructure is configured. Sending volumes are carefully controlled. Engaged subscribers are prioritized. Domains and IP addresses are warmed up gradually.

In other words, the sender starts paying close attention to practices that may have been neglected on the old platform.

Those improvements may have little to do with switching ESPs. They may simply result from better email practices introduced during the migration.

Warmup isn’t optional

One of the biggest mistakes I see is skipping the warm-up process.

Senders want to migrate and immediately start sending at their usual volume. But email doesn’t work that way.

Mailbox providers evaluate reputation, and new domains and IP addresses need to build it.

There is no one-size-fits-all strategy for domain or IP warm-up.

For example, a startup generating a large volume of legitimate new signups every day may have an opportunity to warm up infrastructure using highly engaged transactional traffic. Once an IP has established a healthy reputation, you can flip its role to a marketing email IP while another IP goes through the same process.

Other senders may need a completely different approach.

No universal warm-up plan exists because every sender starts with different data, engagement, volumes, infrastructure, and business requirements.

Don’t choose the shinyest ISP

AI has become unavoidable in marketing technology. Early AI email applications focused on subject-line generation. Now AI can assist with segmentation, personalization, and real-time content creation, and it’s only the beginning.

Those capabilities can be valuable. Perhaps AI can even help email return to its roots as a more personal, one-to-one communication channel rather than another mass-broadcasting tool.

But shiny functionality shouldn’t distract you from the fundamentals. As an email deliverability professional, when I evaluate a platform, I’m especially interested in delivery and deliverability capabilities. Can it identify or remove non-human interactions? Can traffic be distributed appropriately across infrastructure? What control do you have over throttling? What visibility does the sender have into what’s happening on the delivery side?

Many platforms claim great deliverability, yet they offer no transparency into what happens behind their “black box email delivery.

The right questions depend on your organization
Before starting an RFP, ask yourself why you want to move. What do you dislike about your current platform? What capabilities are actually missing? Which problems would migration solve?

If you can’t clearly answer those questions, a migration may simply move your existing problems somewhere else.

International senders also need to think locally

ESP selection becomes even more complicated for organizations operating across multiple countries.

Take Israel as an example. Local platforms are popular there partly because they provide Hebrew interfaces and support during the Israeli work week, Sunday through Thursday. Hebrew also requires proper right-to-left support, something international platforms don’t always handle well.

But localization goes far beyond the user interface. Subscriber behavior, holidays, legislation, working days, language, and cultural expectations vary by market and geography.

A sender operating internationally can’t simply apply the same email strategy everywhere.

When your subscribers are dealing with an ongoing war, displacement, extreme weather, natural disasters, or other major disruption, your next promotional email probably isn’t top of mind.

Email marketers should understand what’s happening in the lives of the people they communicate with. Sometimes the right response is to change the message, delay it, or communicate with empathy rather than simply stick to the marketing agenda.

Know the rules before you try to bend them

Email can look deceptively simple. Write a message, choose a list or segment, and press “Send”.

But it’s a unique channel with technical, reputational, legal, and behavioral rules.

I encourage clients to experiment. Testing is how we learn and evolve. But experimentation works much better when you first understand the fundamentals. You can’t keep skipping the line and get an “out-of-jail card” forever.

A new ESP can give you different tools, infrastructure, functionality, and support. It can absolutely help improve an email program.

But it can’t compensate indefinitely for poor list acquisition and quality, weak authentication, bad sending practices, an improper warm-up, or a lack of understanding of your audience.

Before blaming your ESP, look closely at what’s happening on both sides of that shared responsibility.

Sometimes changing platforms is the right answer

Sometimes the better answer is changing how you use the platform you already have.

Watch the full conversation on YouTube, or see below for Hebrew captions.