7 Email Marketing Tools to Boost Email Deliverability and Engagement

Roughly 361 billion emails are sent every day. And somewhere between "send" and "opened," almost 17% of legitimate marketing emails quietly disappear. No bounce notification. No error. Just gone.

That number used to shock me. Now it just makes me angry on behalf of every marketer who spent three hours writing a campaign that half their list never saw.

Look, most email advice online is surface-level stuff. "Personalize your subject lines." "Send on Tuesdays." Cool. Groundbreaking.

Meanwhile, your domain reputation is sitting in the gutter, and you have no idea. The tools below actually move the needle. Not just on opens and clicks, but on whether your emails show up at all.

1. InboxAlly

Start here. Seriously, before anything else. InboxAlly works by warming up your sending reputation through simulated engagement.

It opens your emails, scrolls them and pulls them out of spam folders. To inbox providers like Gmail and Outlook, that looks like a real human interest. Over time, your sender score climbs, and your placement improves.

What I think most people skip is running an email deliverability test before a major send. Not after things go wrong. Before. Because by the time you notice your open rates tanking, the damage is already done. Catch the problem early, and you actually have time to fix it.

This one is especially useful if you're launching a new domain, recovering from a spam complaint spike, or just have a nagging feeling your deliverability isn't what it used to be. That nagging feeling is usually right.

2. Mailmodo

Okay, this one genuinely surprised me when I first came across it. Mailmodo lets you embed interactive elements directly inside an email. Forms. Polls. Booking widgets. The subscriber never has to click away to a landing page. They just... do the thing, right there.

And the reason that matters? Friction is the enemy of conversion. Every extra click is a person who doesn't complete the action. Taking even one step out of that journey adds up fast across thousands of sends.

Brands running surveys inside emails instead of linking out have reported response rates two to three times higher. That's not a small lift.

3. Lemlist

Cold email has a reputation problem. And honestly, cold email deserves it, because most people do it in the laziest possible way. Lemlist is built for people who want to do it properly.

The personalization here goes beyond "Hi {first name}." You can drop custom images, video thumbnails, even dynamic lines that reference the recipient's company or role. It looks less like a mass blast and more like something a real person actually put together.

There's also built-in email verification, which matters more than it sounds. Sending to invalid addresses tanks your deliverability faster than almost anything else.

Lemlist checking that for you before you send is the kind of thing you only appreciate after you've made the mistake of not doing it.

4. Klaviyo

If you sell anything online and you're not using Klaviyo, I genuinely want to understand your reasoning.

Klaviyo pulls behavioral data from your store and builds flows around it. Someone browsed a product three times, added it to the cart, then closed the tab? There's a sequence for that.

Purchased once, went quiet for four months? There's a winback flow for that, too.

It treats email like a real-time conversation instead of a monthly newsletter blast, and the results reflect that.

The segmentation is deep. Like, genuinely deep. You can get as granular as you want without needing any technical background to set it up.

5. Brevo

Brevo doesn't get talked about enough. It used to be called Sendinblue, which was a perfectly fine name, but here we are.

What Brevo does well is pack a lot into a price point that doesn't require a board meeting to approve. Solid deliverability infrastructure, clean automation, and it handles SMS and WhatsApp from the same dashboard.

For smaller teams running multichannel campaigns, that consolidation alone saves a meaningful amount of time every week. It's not flashy. It just works, reliably, without making your life complicated.

6. Litmus

Here is something that will quietly ruin your week if you don't know about it: the same email can render completely differently across clients. An email that looks crisp in Apple Mail can turn into a broken mess in Outlook 2019. Happens all the time.

Litmus previews your emails across over 100 clients and devices before anything goes out. That alone is worth it.

But it also tracks engagement data most ESPs don't bother with, read time, whether someone forwarded it and how it holds up in dark mode. For anyone running high-volume sends, that insight is genuinely valuable.

7. Hunter.io

B2B marketers building lists manually know this pain: you find a company, you find a contact, but the email? That takes forever to track down. Hunter.io solves exactly that. You put in a domain, and it pulls verified emails associated with it.

The verification is real-time too. It's not just pattern-matching; it's actually checking whether the address is live. Which means fewer bounces, cleaner lists and better sender reputation. Simple tool, real impact.

One Thing Worth Saying

Strategy and tools are not the same thing. A high deliverability email tool solves infrastructure problems.

It will not fix irrelevant content, bad segmentation, or a list that went cold two years ago. You need both sides working together before any of this compounds into real results.

The Bottom Line

Email still converts better than almost every other channel. But "better" assumes your emails are actually arriving. Start with deliverability, build from there, and stop treating it like a technicality. It's the whole game.