Benjamin Gabay

[Ultimate Checklist] Cold emailing? How to boost your opening rate?

Here's a nice technical checklist to boost your opening rate and prevent your emails from arriving as Spam!

Benjamin Gabay
Lead generation
cold emailing

 Here is the "technical" checklist we use to do cold emailing in good conditions! Don't hesitate to give us feedbacks!


1. Assess your strengths and weaknesses



You must first check your messages for "undesirability".

Mail Tester is perfect for this. The tool tells you if you are correctly authenticated (SPF + DKIM + DMARC), if you are blacklisted or if the content you are about to send is likely to be considered as SPAM.

= Mail test


2. SPF registration 


The SPF (Sender Policy Framework) is an issuer authentication mechanism. The SPF protects against SPAM by ensuring that the sender server has the right to send email.

The SPF is a small TXT entry that must be inserted in the DNS zone of your hosting. It looks like this: IN TXT "v=spf1 ~all"

More information on the OVH website.


3. DKIM registration


The (DomainKeys Identified Mail) goes hand in hand with the SPF. It is an authentication mechanism for encrypting the sender's domain name. It is a reliable protection mechanism against SPAM and phishing.

DKIM allows you to add a signature to the header (where all the characteristics of the message are located) of each message sent. This signature is unique to your domain and is provided by your hosting provider.

Here is a key generator that you can use to obtain a private key:

This is also a TXT entry to enter in your DNS zone.

More information on Mailjet documentation


4. Having a public Whois


A decrease in deliverability is observed when WHOIS is private. The Whois allows you to obtain information (surname, first name, address, telephone number) on a domain name.

More information on Mailjet documentation


5. Setting up a reverse DNS


A reverse DNS makes it possible to retrieve a domain name from an IP. It is important because spammers use invalid IP addresses that do not match the domain name. When receiving an email, the reverse DNS lookup checks that the IP of the message is associated with the correct domain name. If this is not the case, the message is blocked.

OVH documentation


6. Use personalized content!


Using custom and dynamic variables is a MUST. Not only does it prevent the email from being considered as a single email sent to hundreds of contacts, but it also allows you to have an extremely powerful conversation with a prospect.

So don't hesitate to use a large number of variables: first name, last name, company name, etc.

Pro tip: write a single sentence or two that you insert as a variable in your email. This sentence will be the marker of the non-automation of your emails. After all, putting a little human in your emails can only boost your opening and response rate ;)


7. Clean up your email database


Limit hard bounces (when the email does not reach its destination: invalid address, expired etc.) by cleaning your database. This is very easy to do. You can simply use the NeverBounce service to do this.


8. Avoid spamming words


Use mail-tester to pass your mail through the Assassin Spam filter. It will tell you how likely it is that your email will be considered spam. Some words should absolutely be avoided. Here is a list of them.


9. Check the reputation of your sending IP


2 things are possible:

  • Check that your open and click rates don't drop. This will already give you a good idea of how your emails are being received.
  • Have a more objective measure of your reputation by using services such as Sender Score which evaluates your reputation from 0 to 100.

10. Presence of an unsubscription link


It's questionable... and counter-intuitive to add an unsubscribe link when it comes to Cold Emailing. But we think it is not only ethical, but also highly recommended. Can you imagine receiving 5 emails from the same sender without being able to unsubscribe? The risks of being put into spam can be really high.

However, if you are certain that your email is written in such a way that automation is undetectable, the presence of an unsubscribe link may be optional. However, we would like to draw your attention to the fact that such a practice does not comply with the recommendations of the CNIL and that Germinal does not recommend this practice.


11. Send your emails from a different domain name


Do not hesitate to send the mails from another domain name (it may be slightly different). This helps to preserve the reputation of your main domain. When you start shooting the emails, go at it step by step. Around 30 emails per day to reach a maximum of 80 to 100 in total per email address. 


12. Do not send email with a personal account.


Do not use an account @gmail / @orange etc...

13. The metrics

Your opening rate must be higher than 35% (which corresponds to the low limit of opening on a sequence of 3 emails). Aim for 55-60% on average!