At Upland Adestra, we’re in the business of solving problems – and in the world of email marketing, there’s no bigger challenge than deliverability.

The good news? Deliverability isn’t just something we’re equipped to handle – it’s at the very core of everything we do. That’s why we proudly offer what we call a front-of-house deliverability service.

Unlike many Email Service Providers (ESPs), where deliverability is hidden behind the scenes, we bring it front and center, where it’s proactive, visible, and fully integrated into the client experience. Because if your emails don’t land, your message doesn’t matter.

Leading Adestra’s deliverability team is someone who knows the space inside out. In fact, you could say that Ken O’Driscoll wrote the book on email deliverability.

To get to the heart of one of email marketing’s biggest challenges, we sat down with Ken to unpack what deliverability really means, what great deliverability looks like, and how our deliverability team helps ensure your campaigns land with confidence – in the inbox.

How do you define email deliverability?

In simple terms, email deliverability is the art and science of ensuring your emails consistently land where they’re supposed to – in your subscribers’ inboxes.

Deliverability breaks down into two key stages:

1. Acceptance: This is the first hurdle – getting your message accepted by the recipient’s email server.
2. Placement: Once accepted, the next challenge is ensuring it lands in the inbox, not the spam folder.

Acceptance depends on factors such as your sending domain and IP reputation, determining how trustworthy you appear to mailbox providers.

Placement, on the other hand, is heavily influenced by how recipients engage with your emails. If they open, click, or reply, that’s a good sign. But if they ignore or mark your messages as spam, that can hurt your chances of reaching the inbox next time.

In short, great deliverability is about building trust both with mailbox providers and your audience.

What does good email deliverability look like?

In general, good deliverability means your email campaigns are reaching 98% or more of your intended audience. That’s not just about sending – it’s about successfully navigating both acceptance and inbox placement.

A high deliverability rate indicates that your messages are being accepted by mailbox providers and making it past spam filters to land in the inbox, where they have the best chance of being seen and acted upon.

It’s also a strong indicator that your sending infrastructure is healthy, your domain and IP reputation are solid, and your audience is engaged. This means your email program is doing exactly what it should: delivering value reliably and consistently.

What are the biggest misconceptions about email deliverability?

One of the biggest misconceptions about deliverability is that it’s simply about ticking a few boxes, such as meeting the bulk sender requirements of major mailbox providers or complying with legislation like CAN-SPAM.

But that’s really just the bare minimum or entry-level requirements you need to even be in the game. Inbox placement is a whole different story.

To consistently land in the inbox, you need to optimize your entire email program for deliverability. That means going beyond compliance and focusing on the following:

• Data hygiene: Keeping your lists clean and up to date
• Audience targeting: Sending relevant content to the right people
• Re-engagement campaigns: Identifying and reactivating inactive subscribers
• Consistent sending practices: Maintaining a healthy cadence and volume
• Monitoring engagement signals, like opens, clicks, and spam complaints

Essentially, great deliverability is earned, not assumed. It’s about building trust with both mailbox providers and your audience – every time you hit send or a campaign is triggered.

What role does domain reputation play in email deliverability?

The reputation of every domain used in an email (not just the sending domain) can influence deliverability. That includes domains used in links, images, and tracking URLs.

This is why we strongly advise clients only to use domains they control. For example, avoid linking to shared-use domains like Google Drive, Dropbox, or Bitly, as these carry a reputation shaped by every other sender who uses them – good or bad.

When you rely on third-party or public domains, you’re essentially outsourcing part of your reputation to unknown actors. And if those domains are abused elsewhere, your deliverability could suffer, even if your own practices are solid.

By contrast, when you use your own domains, you’re in control. Your reputation is built solely on the quality of your own email program, including your content, audience engagement, and sending practices.

In short, if you own your domains, you own your reputation and give your emails the best possible chance of landing in the inbox.

How do structural problems impact email deliverability?

Structural problems within the email program itself are often the root cause of deliverability issues. These aren’t just one-off mistakes. They’re systemic issues that can quietly erode your sender reputation over time.

Some of the most common structural pitfalls include:

• Over-mailing your list: Bombarding subscribers with too many emails, especially without clear value, can lead to fatigue, unsubscribes, and spam complaints.
• Too much promotion, not enough substance: If every message is a sales pitch, recipients quickly tune out. A healthy email program strikes a balance between promotional content and value-driven messaging, offering insights, education, or exclusive content.
• Poor targeting and segmentation: Sending broadly to unengaged or irrelevant segments is a fast track to low engagement and high complaint rates. Without thoughtful segmentation, you risk mailing people who haven’t interacted in months – or ever.
• Lack of engagement strategy: Continuing to send to inactive users without a re-engagement plan can drag down your metrics and signal to mailbox providers that your content isn’t wanted.

Ultimately, great deliverability starts with a well-structured, audience-first email program. That means sending the right message to the right person at the right time – with a clear understanding of what your audience values.

Are there any benchmarks or KPIs Adestra recommends clients track to maintain healthy deliverability?

Deliverability advice is highly industry-specific. A political campaign and a conference organizer, for example, may both send bulk email – but their programs will be structured very differently. That’s why our guidance is always tailored to the sender’s unique context.

That said, there are some universal best practices we always recommend:

• Send mail that people genuinely want to receive
• Ask for permission – even if it’s not legally required
• Keep bounce rates low (under 1%)
• Keep complaint rates even lower (under 0.3%, per Google and Yahoo guidelines)
• Promptly honor unsubscribes
• Never re-subscribe users without explicit consent
• Segment your audience – don’t blast your entire list

But for our clients, this is basic hygiene. They’re experienced, sophisticated senders. Their challenges are far more nuanced.

Take, for example, a client who organizes multiple conferences. One of their events only occurs every two years, and its audience doesn’t overlap with that of their other events. That means the list for that event might go over 12 months without being mailed. Conventional email marketing best practices suggest that you shouldn’t send emails to subscribers who haven’t been engaged in over six months due to the risk of spam traps, reputation damage, and engagement decay.

But in this case, the list is valuable. You can’t just say, “Don’t mail it.” Instead, you need to develop a risk-mitigation strategy tailored to their specific program.

And even then, that plan wouldn’t necessarily apply to another conference organizer with a similar cadence – because every sender’s program is different. That’s the level of nuance and customization our clients expect—and what we deliver.

How does Adestra’s front-of-house deliverability service differentiate itself from other ESPs?

Adestra’s front-of-house deliverability service sits within our Professional Services division. Our deliverability team operates as true consultants – leveraging formal consulting methodologies and advanced data analytics to diagnose and resolve complex deliverability challenges.

We understand that no two senders are the same. With deep knowledge across industries and business models, we tailor our guidance to fit each client’s unique context. Our approach is hands-on, collaborative, and rooted in real-world experience.

Every Adestra client has free access to the deliverability team via the support team for straightforward issues. For more in-depth analysis and strategic support, our deliverability consulting services are available on a billable basis.

Importantly, all domain expertise is self-contained within the Adestra team. This means that we do not rely on external consultants or third-party resources. This ensures consistency, accountability, and a high standard of service.

We’ve deliberately built a model that mirrors how enterprise-grade organizations should approach deliverability. It’s a strategic differentiator – and a game changer in the market we serve.

How does Adestra collaborate with clients when a deliverability issue is detected?

All deliverability issues must first go through a triage process to assess their severity and the commercial impact on the client.

Sometimes, triage reveals a quick fix – like reporting a false-positive block to a mailbox provider. For example, if Microsoft mistakenly filters a client’s mail as spam, we can escalate and get it corrected. That’s the kind of win you want on a Friday evening!

However, if the issue appears more complex, it becomes a consulting engagement. At a high level, our process typically looks like this:

1. Scoping Call: Initial discussion to understand the symptoms and context
2. Problem Statement Definition: Drafting a clear, focused description of the issue
3. Problem Statement Agreement: Aligning with the client on scope and expectations
4. Research & Analysis: Deep dive into data, infrastructure, and sending practices
5. Check-in Call: Interim update to share progress and gather additional input
6. Presentation of Findings: Delivering insights, root cause analysis, and recommended next steps
7. Ongoing Monitoring: Regular check-ins and performance tracking until resolution
8. Optional – Lessons Learned: Supporting the client’s internal review and documentation process

This structured approach ensures we not only solve the immediate issue but also help clients build long-term resilience into their email programs.

What keeps you awake at night in terms of email deliverability?

One word: Spoofing. This is a serious threat, especially when spammers or scammers impersonate a client’s domain to send malicious or unwanted emails. Not only will this damage brand trust, but it can also destroy the domain’s reputation and impact legitimate email deliverability.

One of the most effective tools to combat this is DMARC (Domain-based Message Authentication, Reporting, and Conformance). In layman’s terms, DMARC allows a domain owner to authorize who can use the domain in the From address of a message.

However, implementing DMARC is the responsibility of the domain owner – in this case, our clients. As much as we support and advise, we can’t implement it for them.

While we’re seeing a gradual increase in DMARC adoption, progress is slow. That’s partly because DMARC isn’t always straightforward to set up. It requires a combination of technical expertise, time, and internal resources. And while it’s possible to outsource the implementation, that often comes with additional costs – which can be a barrier for some organizations.

Still, for any brand serious about protecting its reputation and improving deliverability, DMARC is no longer optional – it’s essential.

What about the future of email deliverability?

In truth, I don’t make predictions – but if current trends are any indication, it’s safe to say that the major mailbox providers (Google, Yahoo, Microsoft, etc.) will continue to tighten the requirements for reaching consumer inboxes.

This isn’t about making life harder for senders – it’s about improving the user experience. These providers are under constant pressure to protect their users from spam, phishing, and low-value content. As a result, they’re raising the bar on what they consider to be “wanted” mail.

We’re already seeing this play out through:

• Stricter enforcement of authentication protocols like SPF, DKIM, and DMARC
• Tighter thresholds for complaint and bounce rates
• Greater emphasis on engagement signals – opens, clicks, replies, and even how quickly users delete messages
• More transparency and feedback loops for senders, but also more consequences for poor practices

And while these changes are primarily affecting consumer inboxes, the ripple effects are being felt across the board. Senders who rely on outdated practices or who don’t adapt quickly enough will find it increasingly difficult to maintain inbox placement.

In short, the inbox is becoming a privilege, not a guarantee. And the senders who succeed will be those who treat it that way – by prioritizing permission, relevance, and trust.