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How to prevent emails from going to spam ? Our 12 Tips (2023)

damien ceo mailreach
Damien Brenelière
Co-Founder @ MailReach & Email Deliverability Expert

This guide contains the most efficient guidelines used by cold email experts about how to prevent emails from going to spam in 2023, even if the spam filters are always getting more restrictive. No bullshit, just actionable guidelines, follow them & enjoy life.

A man looking on his computer reading our guide how to prevent emails from going to spam

How to prevent emails from going to spam

Intro : why we are legitimate to write about how to prevent emails from going to spam.

There are plenty of email deliverability guides on how to prevent emails from going to spam, we know it.

Unfortunately, we’ve seen that most of them keep saying the same obvious advices and don’t give the most efficient advices and techniques.

This guide comes from 5 years of intensive cold emailing for more than 130 companies in 40 industries.

The guidelines we deliver in this guide are the ones we’ve used to :

  • Grow from 0€ to 120k€ Monthly Recurring Revenue in 6 months with cold emailing as our only acquisition channel in our previous company.
  • Help raise 56M€ in funding for IPOs and seed rounds with cold emails.
  • Get 75% open rate on average on our cold email campaigns.
  • Spent dozens of thousands of $ to understand and fix deliverability issues for ourself and our customers.

In other words, we know the email game and precisely how to prevent emails from going to spam.

That’s precisely why we decided to work on the most efficient email deliverability solution, composed for now of an email warm up tool and a spam test.

Of course, as the rules change regularly so we’re going to update this guide as often as necessary.

We hope you’re going to find really helpful tips to improve your email results.

How to prevent emails from going to spam

The technical base you need to prevent your emails from going to spam.

Choose the right domain and extension for a good deliverability.

Nearly nobody talks about this.

Surprise : all domains / TLDs are not equal in terms of email deliverability, at least to start.

By making the wrong choices on choosing your sending domain, you can start with a handicap.

Why ? Because some domains and extensions are more associated to spam than others.

A spammer keeps burning domains because his deliverability is constantly dropping.

That’s why his most common behavior is to buy several domains and sometimes, a lot.

And to get plenty of domains, he has to be creative with the name, like using hyphens (e.g. “”) and buy all the exotic extensions : “.xyz”, “.biz”, “.website” etc.

Thus, when you select a domain to send your email campaigns from, be careful not to choose one that can already be considered suspicious.

Which domain extension to choose :

  • Never pick exotic domain extensions.
  • Prioritize the most official ones, such as the “.com” or the one from your country (“”, “.fr”, etc).
  • If you can’t get the “.com” or the official one from your country, pick the “.co” or “.io”.

When choosing the name of the domain :

  • Don’t use hyphens “-“.
  • Don’t use any number.
  • If you need it to include your brand name, add a word before or after it. Here are examples : try, get, agency, consulting, advisory, inc, app, etc.
  • Don’t include potential spam words like “” or any other equivalent, avoid words about money, sex, drugs, weight loss. Use your brain.

For more info on bad and good TLDs, check the Spamhaus TLDs statistics here.

How to prevent emails from going to spam

Choose the good email address format.

  • The ideal sending address represents a human, not a brand or a mix of the two.
  • It has to be nominative (e.g, not generic (e.g Who wants to talk to “” ?
  • For the sender name, use a First and Last name. DON’T use a brand name or a “Brian from XYZ” name, that brings poorer results.

Bonus tip : women have higher open and reply rates than men. Surprising, isn’t it ?

How to prevent emails from going to spam

Setup your SPF, DKIM that’s mandatory. Do the DMARC too.

You may have read it everywhere but you have to do it, that’s mandatory to prevent emails from going to spam.

DMARC is not yet mandatory, it’s a nice to have but we’re pretty sure it will be more important in the near future so do it :

How to prevent emails from going to spam

Set up a custom tracking domain. That’s a game changer on how to prevent emails from going to spam.

Having your own custom tracking domain is crucial, you absolutely need to get one.

Let me explain why concretely so you understand it well.

When you use an email sending / automation tool for your campaigns, your emails are sent with a tracking code and URL inside the body (in the HTML). It’s added by default.

This tracking allows you to know and monitor your open rate and click rate. And, of course, that’s useful to check the results of your campaigns.

This tracking code is always associated to a domain name.

And by default, it’s the same domain name as the other customers of the sending tool you use. It means you share this domain name with a lot of businesses using this tool.

The problem is this : if you don’t set up your own custom tracking domain, your emails will be associated to all the customers of your sending tool who did not set up their own custom tracking domain.

What does it mean ?

It simply means that if you have the same tracking domain as potential big spammers your emails can be identified as spam.

In short, to prevent emails from going to spam, you don’t want to be infected by the bad behavior of others.

By setting up a custom tracking domain, you isolate yourself from others and build your own sending reputation.

Most email sending services allow you to set up your own tracking domain. Look for this feature, check in the documentation or ask them in the support.

If they don’t allow it, switch to another sending service.

You want to know how to prevent emails from going to spam ? The custom tracking domain is an absolute MUST HAVE.

How to prevent emails from going to spam

How to prepare your email list to prevent emails from going to spam.

This part is also very important to learn how to prevent emails from going to spam. Don’t neglect it!

The characteristics of a high opening email list

The following advices is about a B2B use case, if you’re in the B2C field, you can skip that.

To get high open rates and overall great cold email results, that’s important for you to be picky concerning your email lists. That’s important to prevents emails from going to spam, especially for cold emails in 2023.

Here’s what we mean by “picky” :

1. Your email list should contain MOSTLY nominative professional email addresses

When you send your emails, that’s very important that you reach out to a particular person each time, not to generic email addresses like (except if you know this address is associated to one person only).

Sending emails to generic email addresses is most the time shitty for your deliverability.

First, because it’s harder to personalize an email sent to a generic address. No, you’re not going to write “Hi Contact, I hope this email finds you well”.

Secondly because it can badly hurt your deliverability.

Why ?

When you send an email to a generic email address, your email is most of the time forwarded to different people inside the company. Sometimes to dozens of people.

As it’s less personalized, the risk of being marked as spam is multiplied.

Being marked as spam hurts you. You need to minimize this risk.

2. Your list should AT LEAST contain the basic personalization elements such as the name of your recipients and ideally their company name to maximize your results.

Why ? To personalize your content.

Personalization is super important, not only to increase your lead, click or reply rate but to make sure you’re sending a “different” email content to each recipient.

Sending the same email content to hundred or thousands of contacts is a spammy behavior, you don’t want that. Doing this will most likely raise the risk to land in the spam folder.

That’s why it’s very important that you personalize your emails with at least the name of the recipient. “Hi [First Name]” is the minimum, do it.

Bonus tip :  using the company name of your recipient in the first sentence of your email helps a lot increase your reply rate.

3. Your email list has to be TARGETED.

That’s simple, your list must contain people who can be interested by your product or service.

Of course, you can’t really guess if Marie will buy your product before contacting her. But Marie has to be in the target.

Let’s take an example :

You sell fund raising services to startups and small companies. You want to reach out to relevant companies that can be interested to raise funds with you.

When you’re at the step of working on your email list, you have to make sure it effectively contains CEOs / Founders of startups and small companies that CAN raise funds.

That means :

  • excluding people who are not CEOs / Founders like (“PA to the CEO”, “CEO’s Right hand”)
  • excluding companies that can’t raise funds, like public companies / nonprofits, etc.

Why ?

Because if you send irrelevant emails to someone who’s absolutely not in the target, it will :

  • piss off the recipient, get your emails reported as spam and thus decrease your sending reputation
  • hurt your brand reputation.
  • sometimes, make you talk and spend time with irrelevant leads.

How to prevent emails from going to spam

The best source of contacts for high B2B cold email deliverability.

We won’t chit chat during hours, the best place to find quality contacts for your email deliverability and overall email success is LinkedIn, period.

Why ?

  • The data is fresh and up to date : most people on LinkedIn update their profile.
  • The data is rich and complete : you have the name, job title, company, number of employees, industry, etc… That’s a treasure for cold emailers.
  • The data is easy to extract : that’s pretty quick and easy to extract data and find emails out of LinkedIn thanks to third party tools (list below).

How to find quality emails and contact data out of LinkedIn :

We’ve tested many tools over the last 5 years doing cold outreach for a lot of companies.  The tools below are the best in terms of easiness, speed, data quality and number of emails found.

  • The fastest and easiest solution : allows you to directly extract people from LinkedIn with their email and contact data based on a variety of criteria such as job title, industry, employees, location, etc. The data that comes from Apollo is clean, up to date and their email finding rate is great. That’s our #1 pick.

    The main con of Apollo is that they don’t have ALL the LinkedIn profiles on earth. If you’re in a tiny market and you need quantity, you may consider the following solution.
  • The solution that finds the highest number of emails : looking for emails directly out of a LinkedIn results page (the source). This way, you’ll get access to all the profiles on LinkedIn as long as you have a LinkedIn Sales Navigator (Premium) account. Evaboot is for us the best tool to find emails and data out of a LinkedIn results page.The main con : it takes more time / steps than extracting a CSV file from Apollo.

The quality of your email list is an important factor to master how to prevent emails from going to spam, do the best you can to have a great list.

How to prevent emails from going to spam

How to clean your list the best way to prevent your emails from being marked as spam.

Having access to quality emails and data is cool. But once you get the list, it’s not finished.

You still have work to do if you want to get the best results.

Spending time on your list is a key factor to maximize your campaigns results and your deliverability.

This is the list of actions you need to do to before going to the next step :

  • Correct first names and last names inversions : it always happen especially if your list comes from LinkedIn. There’s always people who invert their first and last name. And you don’t want to start your email with “Hi Last Name”. This is not cool and can piss off easily.
  • Remove irrelevant job titles : typically, if you looked for people with “CEO” in their job title, there will be people who are “Right hand to the CEO”, “PA to CEO”. Unless they still are a target for you, remove the “false positive”.
  • Remove irrelevant companies : irrelevant industries, competitors, nonprofits, actual customers, etc..
  • Remove generic email addresses : they will hurt your deliverability over time like explained earlier.

By doing these steps, you’ll improve the quality / relevance of your list, minimize errors and reduce the risk of irritating people and having your emails reported as spam.

A great help to prevent emails from going to spam.

How to prevent emails from going to spam

The best email verification strategy to avoid the spam folder in the long run.

You may have read that before. You have to verify your email list before sending your campaigns.

By verifying we mean checking the validity of the email addresses in your list and removing the ones that are not valid.

Let’s see how to do it the good way.

Which tool to use ?

There’s plenty of tools that verify email lists. We’ve compared a lot of tools and our top picks are Verifalia and DeBounce but if you still want to compare, this article did a nice summary.

How to filter your list based on your verification results :

There are usually three main verification categories : Success, Risky and Undeliverable.

Success is the best but it does not guarantee a 0% bounce rate.

Risky contains mostly Catchall emails and emails which encountered verifications errors (timeouts, etc).

‘Catch all’ are emails that you can’t know if they’re valid or not. That’s a bit like the lottery. But we know from studies we’ve made that around 20% of catch all email bounce. Keep in mind this number.

Undeliverable are the invalid email addresses : the bad and ugly ones.

Here’s what we recommend to follow to protect and maintain a great deliverability.

First, exclude all the undeliverable emails. That seems obvious but do it.

At the beginning, when your domain and your email account is new and you’re doing your first campaigns, we recommend to target exclusively the “Success” ones. It will minimize your bounce rate and you don’t want to have a high bounce rate especially if your email account / domain is young (less than 3 months).

When your email account gets older, we recommend adding catch all emails in your campaigns but the hack is to cap the percentage of catch all emails to 25% max of your list. The remaining 75% are the emails that are Success.

This way, you have more control on your bounce rate.

The worst thing to do for your email reputation is to send big loads of emails to catchall email addresses only and get a lot of bounces.

Remember the rule, you want to have the lowest percentage of bounces on your email account. Aim less than 4%.

How to prevent emails from going to spam

How to write email content that does not land in spam or promotion.

Personalization is important to stop emails going to junk

Personalizing your emails helps you increase your campaign results : open rate, click rate, reply rate and lead rate.

Beyond that, it’s plays a strong role regarding email reputation and deliverability.

Why ?

Because when you personalize, as we told it earlier, you don’t always send the same email.

Sending the same email content to thousands of people is a spam behavior.

Remember to always act human. A real human is not likely to send the same email to 1000s of people each day.

How to prevent emails from going to spam

The toxic elements to avoid to make your content highly deliverable

Spam words : they’re not always the ones you think. You don’t have to talk about viagra, sex or increasing the size of your penis to land in spam. There are plenty of others you’re not aware of.

For example, let’s say that tomorrow, nasty spammers start sending massive spam containing the word “Crypto” and a lot of people report their emails as spam. “Crypto” can then become a spam word because spam filters / algorithms have associated this word to spam. Understand?

Aggressive punctuation : typically, avoid the “!!!“.

Capital letters : NO, DON’T WRITE LIKE THIS, LOL.

Attachments : sending attachments is associated to phishing and hacking. Don’t send any attachment when sending cold emails, never. If you want to share a document, you can use a tool like DocSend that allows you to send a link to your doc.

Links : the fewer links in your email, the better. If you really need to send a link, make sure the website is https secured (to check it, open the website in Chrome and check if you can see the little padlock on the left of the URL). There are many links associated to spam. We’ve seen tons of time people land in spam just because of one link in their content, beware !

Too much image content : the less image, the better for your deliverability. Yes, you can remove your fancy logo in your signature, it can only be better to prevent landing in spam.

Too much HTML formatting : the less formatting, the better. Remember, your email has to be the most human possible. A human does not use complicated HTML when he sends an email. The HTML code has to be the lightest possible with minimum formatting.

In all cases, we strongly recommend you to use our powerful email spam checker tool that allows you to test your email and see exactly where it lands on dozens of inboxes. It gives a huge help to craft emails that land in the inbox.

How to prevent emails from going to spam

How to please your recipients and minimize the risk of your emails being marked as spam

Writing email copies that convert is a skill. Investing time to learn copywriting will help you increase your email results, including avoiding the spam folder.

One of the main factors of a spam spike is having your emails marked as spam.

And people can mark your email as spam for different reasons :

  • Your email is irrelevant for them
  • Your email contains an error they didn’t like (‘Hi Last Name’ for example)
  • Your email is too pushy or salesy
  • It’s difficult to unsubscribe from your email
  • They don’t like your name (racism, etc)
  • They don’t like your offer or your brand
  • Your email pisses them off
  • They receive too many emails
  • They’re having a bad day

That’s why you must be careful, nice and as delicate as possible. Don’t be a cheap vacuum cleaner vendor.

These are our guidelines :

  • As explained earlier (#2.1), make sure your list contains relevant recipients who can be interested by your offer.
  • Use sentences to make your recipient feel selected / considered. Give him the impression you emailed him personally by hand. Example : I found you in my linkedin recommandations, bla bla..
  • Don’t be too pushy / salesy and have a friendly helping approach.
  • Don’t send too many follow ups. Sending follow ups works, but the more you follow up, the higher the risk of pissing off people and being marked as spam. When you send them follow ups, show them you understand they’re busy.
  • Make it easy to unsubscribe. We’ll explain why just after in the next section.

A nice hack can be to ask yourself “How I’d like to be contacted, if someone wanted to email me to sell me the same thing I’m offering?”

How to prevent emails from going to spam

Why having an unsubscribe link is the best option to stop your emails from going to spam.

There is always a debate between including or not an unsubscribe link in your emails.

Some people say it’s better not to put one because it makes your email looks automated and then less human.

Anyways, there’s no debate anymore for us at MailReach. Including an easy to find unsubscribe link is better for your deliverability, period.

That’s pretty simple to understand why.

Because if you don’t have an easy to find link, people will click on “Mark as spam”, that’s it. Even if you’ve said You can unsubscribe by replying “Unsubscribe” to this email.

When people are irritated by your email (and it always happen to at least some % of your list, even for the best of us), they don’t give a sh*t about replying “Unsubscribe” to your email. They just want to ban you of their life, as soon as possible.

To conclude, include an unsubscribe link at the end of your email to minimize the number of spam reports. Don’t play with that.

How to prevent emails from going to spam

How to perfectly send your emails to avoid the spam folder in 2023.

For cold emails, don’t send more than 150 emails per day per email address and domain.

Remember the #1 rule : have a human behavior.

You asked how to prevent emails from going to spam ? This one is super, mega important.

A real human being who use his little hands does not send 2 000 emails per day. Or he’s super fast. You understand.

From all the tests we’ve done, the fewer emails you send per day, the better for your sending reputation and deliverability.

So if you can afford sending max 100 emails per day per email address / domain, do it.

Tip : these numbers are only for your real emails, they don’t include the warming emails.

How to prevent emails from going to spam

If you need to send a higher volume per day, follow these guidelines.

  • Buy different domain names (check #1.1 of this article before)
  • Create one email address per domain. Why ? Because if an address lands in spam it will not affect all the other addresses on the same domain. That’s important.
  • Keep generating positive engagement on each email address with a constant warming.

To learn more on this, we have released a step by step guide on the absolute best cold email deliverability sending strategy.

How to prevent emails from going to spam

Spread out the sending over several hours, don’t send 1 shot blasts.

Again, remember the #1 rule ? Let’s say it again : have a human behavior.

A human does not send big email blast to thousands of people in one second.

Setting a delay between each email helps a lot to land in the main inbox and get high open rates.

Now, real cold email automation tools send emails with a delay.

How to prevent emails from going to spam

Get positive email activity with an efficient warming tool

A lot of people think email warm up is important ONLY BEFORE sending email campaigns.

A one shot warm up done only before sending is not enough to maintain a great email deliverability and sending reputation over time.

You have to constantly warm your email account, before, as a email warm up and during your campaigns.

We have written a dedicated article on the subject : Why to Always Keep Email Warming to Maintain a Great Deliverability.

Let’s explain this.

Getting positive email activity (having your emails opened, clicked, replied, marked as important, removed from spam), is one of the strongest factors to avoid landing in spam.

And that’s logic : if a lot of people open your emails, reply to them, mark them as important, that means your emails are interesting.

Big email providers such as Google and Microsoft take that into account.

If you don’t have a constant email warming activity, you need to have an offer, a subject line and an email copy that everybody loves. This way, you’ll have plenty of positive engagement on your emails.

But, unfortunately, that’s nearly impossible.

Also, when you’re sending email campaigns, you will have a certain proportion of your emails being marked as spam. Each times it happens, it badly hurts your email reputation and deliverability.

A constant warming will help you correct this and balance your activity.

On top of that, having a linear activity is also crucial for your email deliverability.

Not sending email during 2 days, then sending 300 emails, stopping for 1 day, send 200 emails, stopping for 2 days, etc. is bad.

You want a linear activity, with constant positive engagement. This way you’re going to build a strong deliverability in the long run.

This is exactly why we’ve created MailReach email warm up service after spending 5 years of sending cold email campaigns, fixing deliverability and reputation problems.

MailReach helps you reach the inbox and stay there by constantly generating engagement to your sending addresses and domain, and optimize your email content to pass the spam filters with a powerful spam checker tool.

How to prevent emails from going to spam

The conclusion.

If you have read the whole guide, you can easily understand that email deliverability is now a skill, a job or even more, a science compared to the golden age where you could just send email campaigns and have great open rates.

You need to be rigorous, follow the best practices, get help from the right email deliverability tools like MailReach (yes that’s us 😎) to expect really good results in the long run.

But once you do the things right, you will see how positive the impact will be on your email game.

Et voilà like we say in France, we hope you’ve learned at least some very concrete and valuable tips to boost your results.

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