Jonathan Denney

Real-time email validation keeps your mailing list healthy and your email deliverability rate high

It’s a fresh, new week and we just rolled out a cool new feature for you and our loyal customers!

Real-time email validation in your ConvertFlow forms.

Now, all your ConvertFlow forms have an optional feature, SMTP email validation. Here are the benefits of this:

  1. Higher quality lead emails
  2. A healthier email list
  3. Better sender reputation and deliverability rate

So, you may be thinking “why are they making such a big deal about something that sounds as boring as ‘SMTP email validation’”?

Sounds boring, but it’s VERY important for your business.

In simple terms, when website visitors enter their email to opt-in to your list, ConvertFlow can now verify that their email is in-fact a real address, before letting them complete your form.


Yes, that’s right, no more “” opt-ins from people who just want your free report.

Here’s why that can be very important to you and your business…

For more than a decade, email marketing has been a core online marketing channel. Everyone has opted-in to many newsletters and email lists, and we all receive dozens, possibly hundreds of marketing emails everyday.

And because our inboxes have become so saturated, email providers like Google are rolling out features to filter out marketing emails, bundling them into sub-inboxes.


And they use 2 primary factors to determine if your email is for marketing or promotional purposes:

  1. HTML format in the email content
  2. Sender reputation

This is why HTML-heavy e-commerce emails almost always end up in the “promos” inbox in Gmail. These often get much lower open rates than normal emails, and rarely make it to your primary inbox.

But there are exceptions. If you use Gmail, you may have noticed that some promotional newsletters always go directly to your main inbox. So, why is this?

It’s simple. They have a good “sender reputation”.

Your sender reputation score is determined by a number of factors, such a bounce rates, spam complaints, open rates etc.

In other words, a big part of effective email marketing is keeping your email deliverability high. And you can do this by reducing bounced emails.

Of course, to avoid sending broadcasts to emails that bounce, you can have your autoresponder send a confirmation email which requires people to double opt-in to your list. But there are pros and cons to doing this.

For example, if you’re doing lead generation, you may have realized that requiring a double opt-in has a huge downside cost. Many potential customers and great opportunities go down the drain because a lot of people never confirm that they opted-in. Needless to say, this reality can attribute to a lot of lost opportunities and revenue over time.

So, how can you confirm their email is real without sending a double opt-in confirmation email?

Well, here's the answer…

ConvertFlow now makes it easy to have your forms perform a quick email-validation when someone submits them.

All you have to do is turn on SMTP validation for your call-to-action in ConvertFlow, and it will immediately start verifying that new email opt-ins are in fact, real email addresses. And guess what? It does it in real-time!

And if someone writes a bad email address, such as a fake email or an email that’s likely to bounce (due to a slow mail server or inactivity), your ConvertFlow form will automatically ask the person for a better email address.

Cool right?


Now check this out. This part is even cooler!

If someone writes their email and makes a common mistake, such as misspelling of their email provider’s domain name, ConvertFlow will quickly suggest an auto-correction


Now remember, this is an optional feature. You'll need to turn this on for ConvertFlow to perform a SMTP validation, where it pings their specific email address to confirm it’s real.

By default, ConvertFlow will only perform an email format and mx record check, meaning it’ll only confirm there are no weird characters and that the email’s mail server does exist. This is slightly faster than SMTP validation.

However, we highly recommend you activate SMTP validation if you would like to keep your email list healthy, your sender reputation score good and your email deliverability high.

Got a question? Drop us a quick email at, and we’ll be happy to help you out!

About the author
Jonathan Denney
Co-Founder & CTO, ConvertFlow
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Jonathan Denney leads product at ConvertFlow. After running a conversion marketing agency, Jonathan co-founded ConvertFlow with his brother Ethan Denney to help brands build conversion funnels without code or waiting on developers. Since then, ConvertFlow's no-code funnel builder has helped launch 100k+ conversion campaigns, across brands such as Volkswagen, NectarSleep, CampingWorld and more.