Getting started with cold email deliverability

If your cold outreach campaigns haven’t been returning the results you expected, you might be landing in your prospect’s SPAM folders. Even the most well-crafted sales email won’t convert if the message never reaches its recipient. Fortunately, getting into your prospects’ mailboxes isn’t a game of chance and luck. Improving email deliverability is the ticket to closing more deals — and we’re going to tell you exactly how to do it.

Ensuring your emails are deliverable starts before you ever send your first message. A variety of factors can impact where your messages wind up, including:

  • Sending emails from a brand-new account 
  • Misconfigured email records 
  • Too many trackers
  • Language that sets off SPAM flags

The first way to improve email deliverability involves cultivating a healthy domain.

Table of Contents

Improve Your Domain Reputation for Better Email Deliverability

How to Double-Check Your Technical Settings for Sending Emails

How to Warm Up Your Domain to Improve Email Deliverability

What is Good Email Hygiene

How to Avoid SPAM Triggers That Can Hurt Email Deliverability

Other Tactics to Improve Email Deliverability

  1. Don’t Go Overboard on Email Tracking
  2. Check Your Email Signature
  3. Reevaluate Your Subject Lines
  4. Opt for Plain Text Instead of HTML
  5. Test Your Timing and Volume
  6. Offer a Way to Unsubscribe

Where to Get Help Improving Your Cold Email Deliverability

Improve Your Domain Reputation for Better Email Deliverability 

You’ve put a lot of time and effort into building an excellent reputation for your business, and you want that to shine in every cold email. Unfortunately, email service providers (ESPs) don’t care what people think of you in the real world — and your company’s email account has its own reputation.

Every message you send has data associated with it behind the scenes, invisible to you or the recipient’s eyes. This data goes into creating a reputation score that ESPs use to judge whether or not your emails should be allowed into an inbox. Unsurprisingly, a reputation of “0” isn’t going to be very helpful in getting you where you want to be.

It’s best practice to run regular SPAM tests to monitor the health of your sending domain — don’t wait for open rates to plummet first.


The data includes metrics about activity by the sender and domain, such as:

  • How old is the account? Email scammers often open up a new account and send out hundreds of SPAM emails before moving on to a new address. As a result, ESPs are suspicious of emails sent from brand-new accounts.
  • How many emails have you sent to date? No matter how old your email account is, it’s a red flag if you previously sent very few emails. 
  • Are the emails usually delivered and opened, or do they bounce?  A pattern of undeliverable emails can signal SPAM sent without real intent and result in your email being flagged, however unfair that may be.
  • Did prior emails from this domain get filed into SPAM? As with a pattern of bounced emails, a previous history of SPAM flags is frowned upon by ESPs. 

There’s even data associated with the overall activity on your IP address. If you have a dedicated IP, you (or your company) are the only user. You control the activity on the domain. If you share your IP with others, though — perhaps to save on costs — harmful activity by other users of the IP can damage your email reputation, too. 

So, what can you do if you suspect your email reputation may be low? 

First, find out for sure! You can use a tool called GlockApps to run a simple 15-minute email reputation and deliverability test. GlockApps will send some test messages from your domain to its test email addresses, including accounts with popular ESPs like Outlook and Gmail. You’ll be able to see if the test emails wound up in the inbox or SPAM.

GlockApps will also check to see if your sending IP address is on a blacklist. If it is, it doesn’t mean the end of your inbox — you can take steps to remove an IP address from a blacklist.

Glockapps spam test example

If your IP address isn’t blacklisted, but GlockApps still reported a high level of SPAM folder delivery, it’s time to begin some email reputation rehab. You can improve your reputation over time by:

  • Opting for a dedicated IP address
  • Using personalized email addresses like instead of “info@ “or “sales@,” which can appear automated
  • Warming up your domain
  • Evaluating the content of your emails to maximize deliverability 

It’s also essential to make sure your email account and domain settings are configured correctly.

Double-Check Your Technical Settings

Domain Name Server (DNS) records convey information about how your email account sends and receives messages. If these records aren’t configured correctly, it can result in miscommunications that have your emails going straight to the SPAM folder — or not being delivered at all.

Four primary DNS records are vital for email deliverability:

  • MX: an acronym for “Mail Exchange,” the MX record indicates which servers should receive and send email. Without this record in place, you won’t be able to use your email account.
  • DMARC: short for “Domain-Based Message Authentication, Reporting, and Conformance,” this record is a protocol that keeps your domain safe from hacker attacks. It can ward off phishing, spoofing, and other activity associated with SPAM, plus keep you from being suspected of the very same thing.
  • SPF: otherwise known as the “Sender Policy Framework,” SPF records list every hostname and IP address that is authorized to send emails from your domain. If you send from a hostname or IP not listed here, it will likely be marked as suspicious activity.
  • DKIM: this stands for “Domain Key Identified Mail” and is an authentication protocol. It allows the recipient’s ESP to check and see if a recent email was authorized to be sent by the domain’s owner. 

It’s relatively simple to set up DNS records and make sure that everything is shipshape. You’ll need to re-update these records should you ever change to a new ESP. 

Think of your DNS records as your drivers license and your car insurance. You should never hit the road without having both.

If you’ve discovered that your DNS records were not configured correctly before, it’s not the end of the world. While your email deliverability has possibly taken a hit thus far, you may still be able to walk some of that damage back by warming up your domain.

Warm Up Your Domain to Improve Email Deliverability 

When an email domain is new or has no history of sent messages, it’s considered “cold.” Cold email domains are viewed with suspicion by ESPs, so if you send out hundreds of emails from a brand-new domain, many of them are likely to wind up in SPAM folders. This can give your new domain a bad reputation right away. The solution is to warm up your email domains. The email warmup process can also help restore the reputation of existing accounts that have taken a hit. 

“Warm” email domains have a history of sending and receiving real emails that people interact with. Think about the personal email account you’ve likely had for years — after exchanging messages with family and friends over and over again, it’s very warm. 

If you’re trying to launch a new outbound sales effort, though, you don’t have years of time to spend warming up a domain to its full potential. Instead, you can use an email warmup tool to speed up the process. 

Email warmup tools create a network of accounts that send messages to each other. When you sign up for the tool, it will begin sending and receiving test messages on your behalf. The number of emails sent will increase gradually every day — abrupt spikes in volume can be another red flag for ESPs. As messages are sent and received, the tool will mark messages on both ends as read, send replies, and even remove a message from the SPAM folder if it winds up there. 

How email warmup works
Warmbots is a free tool that helps increase your sending reputation

ESPs don’t know that you’ve coordinated this activity — all they see is a positive trend of increased activity over time. This, in turn, builds a good reputation for your domain and increases the chance that your real emails will reach their destination inboxes on the first try.

When shopping around for an email warmup tool, select one that sends emails on your behalf to real inboxes — often other users of the tool — not fake accounts. As everyone’s domain reputation grows through the warmup process, the benefit becomes shared.

You don’t need to pay for an email warmup service, even though there are plenty of paid tools available. Warmbots is a free service that helps raise your sending reputation.

You don’t need to pay for an email warmup service, either! Warmbots is a free tool that you can use to warm up a new domain. And, if your current sending volume is under 300 emails per day, you can use Warmbots to improve the reputation of an active email account. Every message sent goes to another real Warmbots subscriber, and it’s easy to un-enroll at any time. Warmbots currently works with Gmail accounts, and we’re working on quickly expanding functionality to other providers as well. 

It typically takes about four weeks to warm up a new email domain. Warmbots will keep you apprised of the status, so you know exactly when you should start cold outreach to prospects. 

Once your domain is warm and ready to go, regularly cleaning your email lists will help you keep it in good standing.

Practice Good Email Hygiene 

Email cleansing is the practice of keeping your contact lists up-to-date and “scrubbed” free of problematic addresses that bounce. 

Practicing good email segmentation is the first step in improving your email hygiene. Segments are lists of contacts that share a similar trait — the source of a lead is a great place to start. You can also segment your contacts by other data points, including activity, sales volume, industry, and more. Ultimately, there’s no hard and fast rule as to what your segments should be, as long as they make sense for your business. 

blaze verify email verification example

Once you have segments defined, you’ll need to check the deliverability of each email address. This ensures that you’re only sending messages to accounts that can receive them and reduces the likelihood of bounced emails. If your email deliverability tests indicate any contacts can’t receive your messages, you should remove them from your lists immediately.

Next, compare data points between all of the valid email addresses in your segments. Start by looking at:

  • The date someone opted-in to receive emails from you
  • The date on which a contact last opened one of your emails
  • The date on which a contact last clicked a link in an email

If the email addresses have been on your list for at least the past year without any interaction, you can remove them from your list.

Having a high bounce rate is common for spammers, meaning that ESPs penalize senders with high bounce rates.

It’s also important to look at bounce rates for each contact on your list. There are two kinds of bounces reported by ESPs:

  • Hard bounces occur when an email was undeliverable for a permanent reason, such as when an email address no longer exists. If you ran an email deliverability test, you should have caught many of these addresses already.
  • Soft bounces happen when an email is undeliverable for a temporary reason, such as a full mailbox. 

Immediately remove any email addresses reporting a hard bounce — you can’t work around this, and it’s bad for your reputation. While soft bounces may be resolved the next time you send a message, it’s a good idea to set a threshold at which you decide to remove the contact from your list. 

Email cleansing is a lot of work, but it’s essential to deliverability. If you use Growbots, we take care of this for you — our databases are regularly scrubbed to ensure a low bounce rate that you never have to think about. If you’re manually developing your prospect lists, tools like MailTester, Clearout and Bouncer can help you verify email addresses for deliverability.

Avoid SPAM Triggers That Can Hurt Email Deliverability

The content of your emails can actually impact their deliverability, too. Scam emails are likely to more contain images than text on HTML emails or have subject lines written in all caps (and really, that’s just like shouting at your prospect!) ESPs scan for these SPAM filter triggers as well as SPAM trigger words like: 

  • Best Price
  • Money Making
  • Get Paid
  • Miracle
  • Click
  • No Obligation
  • For Free
  • Urgent
  • Winner

In short, if it sounds like words you might hear on a late-night infomercial or see in an ad for a questionable used-car dealership, leave it out of your email.

Other Tactics to Improve Email Deliverability

What if you’ve scrubbed and buffed your email list, triple-checked DNS settings, warmed up the inbox and have hired the world’s greatest cold email copywriter…but still aren’t seeing the results you want? It might be time to dig even deeper and enact tactical anti-SPAM measures. Start by evaluating these six things that can have a lingering impact on deliverability: 

1. Don’t Go Overboard on Email Tracking 

Email tracking sounds like a great feature — see exactly when your message was delivered and how the recipient interacted with it! Unfortunately, there’s a negative side to open and click tracking. If overused, it can diminish email deliverability. 

Each time you decide to track a variable, your ESP inserts additional data into your message in the form of tracking pixels. You may also inadvertently add trackers by placing a URL in your email. 

Because tracking pixels can be used to collect all manner of information, it’s possible they can be abused by bad actors. As such, ESPs are wary of tracker-heavy emails and may mark your message as SPAM. 

Email tracking pixels are exactly that: a 1×1 pixel image with a bit of script inserted into the HTML code that loads once someone opens your message.

It is possible to strike a nice balance between collecting the data you need without overusing tracking and reducing deliverability. Going forward, consider these best practices to help you land in the inbox: 

  • Only turn on tracking for 10% of your campaigns. This allows you to establish a baseline without going overboard. You can also utilize tracking during A/B tests.
  • If you’d like to include a link in your email, don’t hyperlink an entire URL. Instead, anchor it with text.
  • Set up a CNAME record in your DNS settings. This can help you maintain good deliverability when you do need to use tracking pixels.

2. Check Your Email Signature

Take a look at your email signature — is it plain text or loaded with elements like your photo, company logo, links, and buttons? Heavily stylized email signatures can include those pesky trackers that ESPs don’t like. 

To really optimize every aspect of your email deliverability, it’s recommended to keep your signature as light as possible. Do include your essential contact details. Don’t link to every profile you have on the Internet.

3. Reevaluate Your Subject Lines

A great subject line can be the start of a positive cycle. When your subject line entices the recipient to open your email, your domain reputation improves. In turn, a better domain reputation positively impacts deliverability.

Personalized email subject lines do a great job of catching the recipient’s eye and enticing them to click. And remember — always be honest about your identity and intent. Never use a false fear tactic, such as saying a nonexistent bill is due, in an attempt to get a higher email open rate. 

4. Opt for Plain Text Instead of HTML

Image-heavy HTML emails look great, but they’re not easy for ESPs to scan and review. There’s a ton of data sent with every HTML email, and ESPs know that bad actors may use it to conceal malicious trackers. Plain text emails are more easily ‘readable,’ so your recipient’s ESP knows that there’s nothing questionable hidden in the message. 

Plus, plain text emails are great for outbound use — they look more like a personal business letter or friendly note and less like a marketing blast sent to thousands of subscribers.

5. Test Your Timing and Volume

With the ability to schedule emails comes great power — wield it like a human, not a machine! Real people don’t sit at the computer and send out an email every ten seconds for eight hours straight. Any outbound automation should be throttled to send like a person in batched intervals. Day-to-day growth should be scaled gradually, not spike dramatically.

Curious what the best time is to send an email? Try out our Email Time Optimizer to find out what time is best for your industry & personas.

Quality prospecting tools like Growbots will time email sends for you, keeping pace and volume similar to what you would send when doing it manually. (You, of course, get that time back to do other things). 

6. Offer a Way to Unsubscribe

The United States CAN-SPAM act requires that you give your recipients the opportunity to unsubscribe from future communications. This is typically set up as an “unsubscribe” link in your email footer, but it doesn’t have to be. 

Because links can negatively impact deliverability, Growbots subscribers have the option to use unsubscribe text instead. You can, too — place a line in your email that instructs the reader to reply if they’d like to be removed. For example:

PS. Not interested? Reply to this email and let me know; I’ll remove you from my list right away. ” 

You do, however, actually have to remove anyone from your list if they email you back and request it. Don’t treat that “unsubscribe” reply as a chance to further engage in sales.

Get Help Improving Your Cold Email Deliverability

Manually improving email deliverability can be a manageable task on small contact lists, but as your address book grows, it may become too much to handle. 

Luckily, you don’t have to monitor and manage email deliverability on your own. Growbots is a prospecting tool that takes the work out of building a great domain reputation and connecting with qualified leads who are interested in what you have to offer.

Growbots is the only true all-in-one solution, combing 100M+ contacts with email automation and strategy consulting. Learn more here.

We start by curating lists of prospects that fit your ideal customer profile and continually clean our databases to maintain an incredibly low bounce rate. Contact your custom list of leads directly with scheduled drip sequences — using Growbots is just like sending an email from your normal inbox but easier, since we’ll only show you the warm responses. No more wasting your time on emails that aren’t going to lead to a sale. 

Book a demo or jump right in with our 3-month bootcamp special to get started on building great email deliverability and reach exactly the kind of leads you’ve been seeking. You’ll be paired with a Growbots Strategy Consultant who’s on hand to help you build your best prospecting sequence yet — from setting up your account to crafting an irresistible drip that your soon-to-be-customers will love.

See also  Outbound Expert of the Week - Melvis Courage

Boost your outbound with our all–in–one lead generation platform!

Access 200 million contacts with the help from outbound experts.

Sign up for a free trial!
Chris Zawisza

Chris Zawisza

Head of Sales @ Growbots - laser-focused on the growth of Growbots’ customer base. Always eager to brainstorm and explore new ideas.