How to Improve Cold Email Deliverability in 2024

email deliverability and reputation
Rachel, a Sales VP at a growing tech company, noticed her team’s emails started landing in the dreaded Spam folder for their recipients.

Understandably, Rachel was concerned. She knew she had to quickly improve her company’s email deliverability and domain reputation.

She’s not alone. Multibillion-dollar technology companies are struggling to improve their email deliverability. Emails from companies like Google, Brex, Intuit, and Canva are consistently ending up in their recipients’ spam folders.

even google struggles with email deliverability and domain reputation
That’s right: even Google’s own emails are ending up in Gmail spam folders.

That’s bad news for a lead generation team accountable to setting appointments, and quota-carrying sales team who have a number to hit. 

Let’s get back to Rachel. She was understandably worried that her team’s follow up emails, proposals, and agreements were landing in spam. Something had to be done. They were burning through their list of prospects, not to mention a hole in their pocket.

First, why is this happening? 

Over the last few years, email ISPs (Google Mail, Outlook, et al) are increasingly flagging emails as promotional mail, updates, and spam. Google especially is investing a lot of bandwidth into stomping out mass emails, so following these best practices below is more important than it’s ever been.

Companies that are sending outbound emails need to be diligent and build a checklist of processes to follow to assure their emails have the best chance of getting sent to a recipient’s main inbox. To have your emails land in the primary inbox, you need to build and maintain a strong domain reputation for your email address.

With that out of the way, here are the steps we outlined for Rachel to increase her sales team’s deliverability.

Look and Behave like a Human 

Let’s start with the basics. Don’t worry, this will turn into the deep dive you’re hoping for soon. 

One of the keys to sales and lead generation is acting like a human being. Cold email is no exception. 

Add a photo to your email profile photo so your prospects see your photo when they see an email. This humanizes the experience, and shows you might be a person instead of a bot. This will also increase reply rates, which will level up your email reputation.

One should never pass up the chance to strike a “blue steel” pose.

Have a Great Email Signature, and Optionally, Show Your Face There, Too

Hubspot offers a free signature generator that you can fully customize. Check it out here.

Putting your face on your emails in a couple of places will help make you look human. Not surprisingly, behaving and acting like a human and not an automated email campaign builds trust. Trust helps prospects act more receptively to hearing about a new offering. Most importantly, it makes it more likely that your emails will get a reply, which helps with overall email delivery and domain reputation. 

If you don’t put your picture in your signature, consider putting an image of your logo instead. Help your email stand out from the bevy of others we all see every day as executives.

Plan for the Black Swan Event with a New Domain

It doesn’t happen often, but when it does, it’s tragic: a company’s domain gets blacklisted by email ISPs (for days, weeks, or even months). If your sales or marketing team tanks your email reputation, your entire company risks having their emails sent straight to promo and updates folders.

This means that an important follow-up email from a founder to an investor can go to spam. Or a renewal agreement from an Account Manager, or an invoice from your Accounting team – it could all end up going unread. 

How do we hedge against this disastrous scenario? By never allowing it to happen in the first place.

To do this, you have four options:

  1. Create a new domain TLD (e.g. instead of We recommend you only consider .com, .co, .net, .io, .ai top level domains for this. Deciding on a .biz for this will not strike prospects with the curious intrigue you are hoping for.  
  2. Create a subdomain (e.g. at your existing domain name. This shifts the email reputation to the subdomain, away from the root domain. It’s mostly treated as a separate domain name altogether. If you do this, use something like,, or 
  3. Insert ‘get’ or ‘use’ or ‘try’ so you can still use a .com TLD (e.g. Have this redirect to your normal domain name, because prospects will go to this site to look you up.  
  4. Use an email vendor like Sendgrid or Mandrill so they absorb the reputation hit instead of your domain. They are awfully aggressive, though, when it comes to booting you if your bounce rates or unsubscribe rates are too high. If they flag your account, up they’ll halt all your outbound emails at once, and you will be left scrambling to find another vendor. If you do this, always have a back-up mail service ready to go. 

Consider what’s most technically feasible for you right now and get started. 

If you’d like to use a subdomain, here’s our guide on how to set one up in Google Mail.

Once the domain’s set up: check if your new domain is on any blacklists here. It is not uncommon to see that you’re already blacklisted before sending a single email. Follow the rest of the steps below to get whitelisted. 

Three Acronyms You Need to Know in your Sleep: DMARC, DKIM, SPF

This one’s not optional: you have to set up DMARC, DKIM, and SPF. Here’s how to do it with Google Mail: 




While there’s a slight learning curve to setting these up, especially if you’re not technical, it is necessary you do this. To put it as simply as we can, these authenticate your email server and prove to receiving mail Internet Service Providers and mail servers that your emails were actually sent by the users authorized by the owner of the domain. 

While tricky, DMARC is very vital. 

Warm up the New Domain/Subdomain

Your new emails will most likely go to spam if you’ve purchased or configured a new domain/subdomain in the first 14 days. Send low-volume email initially to ‘warm-up’ the domain, while making sure message quality remains high. 

A sample warm-up schedule. There’s no harm in warming up at an even slower rate, if you can. 

How do we systematically warm up these emails?

Send, receive, and reply to lots of emails before engaging in any actual outbound lead generation. 

As often as possible, send out new emails and make sure they get replies. Sign up for newsletters and reply to them. Email friends, colleagues, send questions and then ask follow-up questions when they reply. You can systemize this with a daily checklist. Get super resourceful here to set the stage for deliverable emails down the road. Don’t be afraid to get creative. 

We use our customer’s email addresses to converse and reply to other customers, marking their emails as ‘important’ to evade the dreaded Updates, Promo, and Spam folders. This takes a lot of set up, and a lot of routine execution, but it is well worth the effort. For best results, continuously do this in the background while you are engaging in outbound email lead gen.

For even better results, do this with a couple emails continually: one for outbound, and another for your critically-important sales emails. Use the ladder for working pipeline and customer correspondence. For ultra-valuable contacts, it’s absolutely imperative that your email hits the inbox. 

Use a Service or Two to Monitor Your Email Reputation

How do you know if you’re ending up in spam folders for different mail servers like Gmail, Outlook, Zoho, et al?

Web admins use Google Webmaster Tools to identify issues with websites. Similarly, email sales and lead generation teams need to use a toolkit to monitor their email inbox deliverability and domain reputation.

Here are some to get you started:   

Pick a few of them, and test them side by side. Run with the ones that give you the most actionable insights. We re-tool here quite regularly. Here’s a quick guide on how these tools work. 

Shoot for a Bounce Rate Below 5%

You need a 10% or better bounce rate (5% or better is ideal). This tells email ISPs you’re emailing an opt-in audience list and they want to hear from you. 

Here are a few products we’ve tested or currently use as part of our deliverability stack to monitor campaign health:

A few of the validation APIs we’ve tested to date –

We highly recommend that you pick out your top 3-5, and then test them against a decent sample size of email addresses. Send emails to every email on the list (using a burner email address), and rate each against the following metrics:
•Correctly delivered %
•False positive (didn’t bounce) %
•True positive (correctly bounced) %
•Unknown emails successfully delivered %
•Risky emails successfully delivered %

Reduce Reliance on Emails

Not one to waste time, this anthropomorphic teddy bear favors the multi-channel sequence.

Okay, this one is a bit removed from email deliverability per se. But I’d be remiss if I didn’t mention it. If you have a 15-touchpoint email sequence, and convert 5 of them to call touchpoints, you’re lowering email volume by a third, which will probably help your overall email reputation. The exception to this is if your email reply rates are especially high for your emails #10-15. But even then, you should make calls so you can mention it in your emails, to increase urgency.

We highly recommend you test phone calls. This is especially true for traditionally personable ideal customer profiles like Heads of Marketing, Sales, Learning & Development, HR, and Communications. 

At Convert.AI, the bulk of the leads we generate for our customers are booked over the phone. For some of our customers, upwards of 80% of leads are generated via calls.

Why? it’s easier to rise above the noise with a call. Executives get dozens of emails daily, but usually not the same volume of calls.

If you have a team member with a commanding phone presence, quick wit, and curious intrigue, you’ll usually book more leads over calls instead of emails. Of course, do both. But don’t forget to complement your inner Kurt Vonnegut with your inner Morgan Freeman. They make one hell of a team. 

Dry powder: Warm-up Another Email in the Background

We are of the opinion that you can’t be over-prepared when guarding your team’s email deliverability. Account for the worst-case scenario, which is that your email deliverability falls wayside. Expect that your emails might suddenly land in “spam jail”, at least temporarily. 

We pioneered a process around this that we are unveiling for the first time. Here’s what you do: Warm up another email in the background from the very beginning, so you’re always prepared to switch if you ever need to. You’ll be glad you did the upfront legwork here. 

If you end up swapping your email for the one in reserve, your work is not done yet. You’ll need to set up another email to run in the background. Rinse and repeat. Never get caught off guard. 

Honorable Mentions

  • If possible, rotate between different emails if you’re sending >400 daily emails from any given email address. 
  • Add novel value in your outbound campaigns, as much as possible. 
  • Instead of appointment setting call-to-actions, ask questions they can reply to, to start a dialogue. This increases reply rates, which not only generates more leads, but preserves your email reputation.
  • Take caution when inserting URL links in cold emails (and using link tracking) as these can greatly impact deliverability and send emails to the dreaded Spam, Updates, or Promotional folder. One good rule of thumb is to avoid sending more than one link in an outbound email until a contact has responded.
  • That said, you should still include an opt-out link in your email, or end them saying “Feel free to say no if this isn’t a good fit, I value your time.” While it’s no fun to see people click this, it’s much better than the alternative, getting marked as spam. 

The Outcome 

Remember Rachel, and the story we opened with? You might be wondering what happened.

After a few weeks, Rachel had a deliverable new email address that was routed straight to the main “inbox” folder for recipients.

More importantly, she had a weekly pulse on her email deliverability and was prepared with a downside protection plan if her emails suddenly fell wayside again. Most importantly, Rachel’s team saw a dramatic boost in her open rates and consequently her email reply rates.

Rachel ended up using a service like Convert.AI to manage this for her sales team, but if you’re able to systemize a process that you can measure and track, you can also do this in-house with the right people, systems, and feedback loops.

Interested in leveling up your outbound lead generation and sales campaigns?

We know more about it than most. 

Talk to one of our executives about your team’s outbound lead generation.

Subscribe to the Convert.AI blog.

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