Earlier this year, Google’s core updates hit the outbound marketing community hard through raising the standards by which legitimate email is judged. Complete with smart AI-driven spam filters, these updates seemed to create an impenetrable barrier to the inbox and carve a direct path to the spam folder. Industry-wide, email deliverability suffered while domain reputation took a beating.

But, after having a few months to reconsider our approach to outbound email marketing, we and our clients have found that the situation isn’t so bleak. This guide offers a step-by-step approach to preparing your email domain and structuring your messages to ensure the best possible email deliverability while developing and protecting your email reputation.

Don’t forget: if your email deliverability goes down, that includes emails being sent to current clients, not just new prospects you’re targeting via outbound! So, it’s really important to always practice good email hygiene if you want to successfully reach new and existing contacts.    


Authenticate Your Email 

Email authentication is your administrator’s concern. Still, without getting too deep into the tech weeds, it doesn’t hurt to know what it is and why it’s important.

The two most important acronyms you should are:

  • DNS – Domain Name System
  • DMARC – Domain-based Message Authentication, Reporting and Conformance

Your DNS record is your domain’s ID. It converts your host name (your.name@revenuezen.com) into an IP address that the mail server can read, thus confirming where the messages are coming from. DMARC is the protocol that blocks outsiders from hijacking your domain for nefarious reasons, such as phishing scams and email compromise attacks, such as receiving a bogus email request from your CEO requesting your social security number. 

Together, DNS and DMARC create a secure pipeline from your email domain to the mail server to limit the risk of outside attack. If you simply ask your administrator to make sure the DNS and DMARC records are up to date, your work is done. They’ll take care of the rest.


Warm Up Your Email Domain

If your email domain is new and has seen little or no activity, spam filters will tag your outgoing messages as spam by default. The only remedy for this is to warm up your email domain before sending to live prospects. Even if your primary domain has a good email reputation, new sub-domains are subject to the same scrutiny and must be warmed up before going live.

Warming up an email domain is simple but a little tedious. First, compile a list of “friendly” email addresses. This list should consist mainly of business addresses, but a few personal emails are fine. Most importantly, your recipients must know they are playing a role in the warming up process and be willing to respond to your messages promptly and naturally. 

Using natural language in this email exchange is important since AI-driven spam filters are good at spotting fakes. Do not copy boilerplate language you find on the internet or use Lorem Ipsum text and expect to get any positive results. The point is to simulate an actual human-to-human email exchange, and both the sender’s and recipient’s language should support that end.

Create a schedule for your warm-up activity but keep it flexible. If you consistently send to 150 people every day at 5:00 p.m., the activity will appear robotic and could cause damage to your email reputation before you even begin building it. Try sending to half of your list in the morning, a quarter in the afternoon, and the remainder around the close of business. You can adjust this formula based on the day of the week, but the point is to make these exchanges look as authentic as possible. Encourage the people you’re emailing to respond. Have a natural conversation. Ask them what they’re making for dinner! Make it look real, and the Google overlords will reward you.

Expect to see some positive results in around 60 days. Depending on the size of your list and the volume of activity, you could shorten this time to 30 days or even a couple of weeks.


A Clean Email List – How to Get and Keep One

Building vs. Buying a List

If you’re not sure whether you should  build or buy a prospect list, try building one first. With the free and low-cost tools available today, it doesn’t make sense to drop a ton of cash on a quality list when one can be built in a couple of hours. If you find you don’t have the time for list building, make sure the list broker you work with has a good reputation.  

But whether you build or buy your list, you will still need to maintain it. Email lists deteriorate every 30 days as people change jobs, get furloughed, and companies dissolve. Pay attention to your bounce rate and match the data against your list to determine if a prospect should be purged or updated. Schedule routine list maintenance on an as-needed basis to start, then every 15 to 20 days to stay ahead of the 30-day curve.

Before You Build, Do Your Homework

Why would a Quality Assurance Manager be interested in software that helps HR executives manage payroll? She wouldn’t, but all too often prospect lists are built on generalities and similar-sounding titles without regard to specific roles and responsibilities. 

One of the advantages of building your own list is the control you have over its contents. A list of 1,200 prospects might only yield 800-900 ideal titles. Without scrubbing the list, the 300-400 off-target prospects could pose a risk to your email reputation if even a fraction of them flag your message as spam. Over time, this can cause A LOT of damage. 

Purchased lists are not exempt from including off-target contacts and bad data, so if you’re going to scrub a list before using it, it might as well be your own.


General Best Email Formatting Practices

Subject Lines

Being the first piece of copy your prospect will see (and judge), a well-crafted subject line is critical. Your subject line should include a relevant pain point or specific benefit, it should come in at under 25 words, and above all it should use warm, human-sounding language free of trite buzzwords and hackneyed phrases typical of spam.

Instead of this… Try this…
Sales magic!! Close 100%!! GUARANTEED!! Hey {firstName}, close 30% more in Q2
Are you free this week? Got a minute to solve [specific pain point]?
YOU’RE INVITED! {firstName},  talking SEM on Tues. You in?


  1. Sales magic!! Close 100%!! GUARANTEED!! First, stay away from bombastic claims that provoke immediate skepticism. Nothing is 100% guaranteed, so don’t say it. Also, never use all caps for any word or, more alarmingly, your entire subject line. Use exclamation points sparingly, if ever – and never more than one.
  2. Are you free this week? Free for what? Most executives are not, and this clickbait-style subject line won’t pique their curiosity. However, if you suggest helping them with a vexing pain point, you might grab their interest – at least long enough to open your email.
  3. YOU’RE INVITED!  This combines the worst of all worlds – it’s vague, in all caps, and punctuated by the official symbol of hyperbole. Prospects are not interested in your webinar, demo, or whatever it is you’re trying to get them to pay attention to. They want to know what your service or thingamajig can do for them. It may be a challenge to explain much in space as short as a subject line, but you need to give them something of value. Otherwise, this kind of subject line is just an invitation to click the MARK AS SPAM link.

A word on snippets. Notice the camelcase text within curly braces on the right. This represents a snippet that can pull specific information – first names, titles, business names – from the database and place it in your email. Most commercial CRMs have this feature, but the snippet format will vary. If you’re not sure how this feature works in the CRM you use, check with your administrator.

Optimize Format & Copy to Avoid Email Spam

This section applies more to human spam filters but is nonetheless crucial in avoiding a one-way ticket to spamville. Poorly designed emails with unnatural-sounding copy, imposing blocks of unbroken text, and grammatical acrobatics will bore and annoy your prospect, perhaps to the point of tagging your email as spam just to never have to hear from you again.

Shorter copy is better, but don’t let this suggestion limit you. The length of your email should be proportionate to the information your prospect needs to make a decision. 

But whether your email is three paragraphs or five, avoid fluff as though it bites. Fluff is any unnecessary text that lends nothing to your message. You don’t have to be an expert grammarian to avoid fluff. On a notepad, list the key points you want your email to cover and write about them in strong, simple, active-voice sentences.

At the risk of sounding ridiculous, here’s what I mean by fluff copy:

“It was 2009. The country was struggling under the economic burden of the Great Recession and tech startups were finding it hard to gain any financial traction. Advertising budgets were vapor-thin, and staff cutbacks were forcing founders and CEOs into interdisciplinary roles such as SEO, SEM, and PPC. That’s when we heard the call and dedicated ourselves to helping startup tech companies navigate the murky waters of…”

Ooof! What is wrong with saying:

 “We’ve been helping tech startups manage their digital ad spend since 2009” ?

Also keep in mind that the bulkier the verbiage, the greater the risk of one or more words triggering spam filters. If this happens, your prospect will never lay eyes on your riveting tale in the first place.

Should You Use Images?

Branding your emails with your company logo or other images will look professional, but it’s not worth the risk. Depending on the sensitivity of the spam filter, .jpg and .png images might be interpreted as spam. It is safer to use a personalized line of text that explains who you are and what you have to offer than trying to project a seamless, professional image with elements that may land your message in the spam folder. It will also give you a chance to develop your skills as a copywriter.  

What About Links? 

Spam filters are on the lookout for suspicious hyperlinks. Raw hyperlinks of 50 to 100 or more characters are not only ugly, they’re the trademark of spammers who aren’t as concerned about aesthetics as they are hooking a few unsuspecting victims. 

If you must include links in your email copy, the best practices to follow are:

  • Limit the number of links to one or two
  • Embed your links in a small portion of copy. For example: 

Rather than…

For more information and access to our library, visit us at: https://www.ipsumlorem.com/resources%50%/downloads/%2750%


For more information and access to our library, please visit our Resources Page.

And Attachments?

One word on attachments: Never!


We aren’t robots. In fact, this Google update should remind us that marketing is a human-to-human profession. Yes, these updates made outbound email marketing a bit more challenging, but we should remember that they were installed to protect legitimate businesses from the bots and crackpots that poison the email ecosystem. Therefore, as professional marketers, we should take it as a compliment and up our game accordingly.      

We love creating email marketing strategies full of stellar copy. We’ve even helped some organizations achieve 82% email open rates. Say what?! Contact us if you could benefit from something like that.

Tom Cholewa

Tom is a Sr. SDR at RevenueZen. He works with various SaaS start-ups to create as much sales pipeline as they can handle. When he’s not writing email sequences, LinkedIn content, or building targeted prospecting lists, he’s brushing up on the latest trends in K-Pop so he can have a conversation with his 12-year-old daughter. Occasionally, he’ll catch a St. Louis Cardinals game.