The best tips to improve the deliverability of your emails!

2 billion emails are sent per month; at the time of GDPR, records were broken with more than 100 million email sends per day. Email remains a preferred communication channel, whether for institutional, transactional, or marketing communication—whose marketing email statistics are to be monitored.

So it’s important to take the utmost care with your emails to optimize deliverability.
It should be noted that more than 14% of emails do not reach the inbox.

First of all, let’s define deliverability: it refers to the number of messages that reach the recipient’s main inbox, without being deleted, filtered, or put into a spam folder.

Deliverability can be impacted (positively or negatively) by different criteria:

the quality of the contact list,
the targeting of this list,
the content of the message,
the sender’s reputation,
the sending frequency,
open rates, unsubscribe rates, and bounce rates.

MAINTAIN GOOD CONTACT LIST HYGIENE

Data collection

The thing not to do is to import a contact list without verifying it.
The collected data must be, on the one hand correct :

not contain typos,
not contain inactive addresses,
not contain non-existent addresses.

There are services like “neverbounces” or others with whom most routers have partnerships, allowing you to verify your email addresses.
Sending emails on a list that contains many “bad” email addresses will lead to a much higher bounce rate, which will negatively affect your e-reputation and therefore your deliverability.

Opt-in

In addition, with

GDPR, obtaining consent from people in B2C is mandatory.
Your online forms must obligatorily include an opt-in field. This allows you to send emails to people who want to receive them, and therefore your open rate will necessarily be higher. Likewise, the unsubscribe rate will potentially be lower because your contacts will be interested.

The open rate as well as the unsubscribe rate are important factors that affect deliverability. The higher your open rates, the more your deliverability improves. Conversely, the higher the unsubscribe rate, the more your deliverability is negatively impacted.

Double opt-in

The double opt-in is a very good way to improve the quality of your contact list.
The principle is to send an email to a person who has signed up (by giving their consent). The email contains a link inviting them to click on it to ensure that the email is legitimate and really exists. This helps avoid typos errors like “@gmil.com instead of @gmail.com.”

Inactive contacts

Inactive contacts are much less likely to open your emails and therefore reduce your email open rate.
If a contact is inactive, it’s possibly because they are no longer interested in your products/services. You should therefore remove them from your mailing lists.
You can consider a contact inactive if they have not opened your emails for 6 months.

Captcha

Set up captchas/reCaptchas to prevent bots from submitting your forms by polluting your database with “fake” contacts.

Segmentation

Once your contact database is “clean,” it is essential to segment it. Indeed, it’s not relevant to send emails on certain topics to people who wouldn’t be interested, because that would lower the open rate.

Segmentation can be done using different criteria:

demographic,
behavioral: browsing the website, interests, etc.

THE CONTENT OF THE MESSAGE

Taking care of the message content helps significantly improve deliverability.

Subject

The subject is the first thing the person will see in their inbox. It’s what will make them want to open the email.
The subject should not contain:

keywords such as finance, taxes, money, super promo, etc.: unless it’s legitimate in those areas,
words in uppercase and special characters: example SUPER PROMOS!!

It can include:

emojis,
personalization: for example the person’s first name in the subject.

Text/image ratio and length

A text/image ratio of 60%/40% is recommended.
In addition, the email must not be too long, otherwise some email clients such as Gmail may truncate it.

Email weight

The weight of the email can have a significant impact because an email that is too heavy has much better chances of ending up in the spam folder.
It’s recommended not to exceed 500KB. So pay attention to the weight of the images inserted into the email.

Unsubscribe link and online viewing

Contacts must have the ability to unsubscribe easily.
The unsubscribe link must, at minimum, be included in the email footer. It’s even better to include 2: one in the header and the other in the footer.

Similarly for the online viewing link, with some email clients the display may not be optimal. The person should therefore be able to view the email in their browser.

Provide a text version

Some email clients (such as Outlook, for example) may have trouble reading your email. One solution is to provide a plain text version.

Optimize the HTML

Don’t hesitate to test the HTML of your email on websites such as W3C’s. It’s common to forget to close a tag, for example.

Responsive design

Since emails are increasingly viewed on smartphones, your email must be responsive designed (display correctly depending on the different devices).

Personalization

Personalizing emails consists of adding different contact fields (such as first name, last name, etc.)
Personalizing the email (especially in the subject) helps significantly improve the open rate.

A/B test

Use A/B testing to test your different email versions and see which one performs the best. A/B testing can also be done at different send times.

Test your emails

Don’t forget that, before starting your email campaign (or sending your newsletter), you should send the emails to yourself to check whether the rendering is correct.

SENDER REPUTATION

Your sending server must go through one or more IP addresses. There are 2 types:

dedicated IP addresses,
shared (mutualized) IP addresses.

It’s important to monitor the reputation of the IP address because if you’re on an IP blacklist, you have much less chance of reaching the inbox and therefore the spam rate will be higher.

Dedicated IPs

You are the only one sending emails from this IP. It’s you who manage your reputation directly. Use a dedicated IP if you send a large number of emails at a recurring frequency, without spikes from one send to another.

To start with a dedicated IP, you generally need to go through a warm-up phase. This involves making different email sends while gradually increasing the number of sends.

Shared IPs

You share this IP with other companies and therefore share the reputation.
The advantage of using a shared IP is that if you don’t send emails regularly and you create sending spikes, that spike will be absorbed by the pool of shared addresses .

AUTHENTICATION

Authentication standards make it possible to give the sender (domain name) legitimacy. This doesn’t prevent being in SPAM, but webmails (Gmail, Yahoo, etc.) and ISPs (Orange, SFR, Bouygues, etc.) will be more likely to allow emails through to the main inbox. In addition, this secures your domain name so it can’t be used by spammers.

It is strongly recommended to set up these 2 protocols:

SPF (Sender Policy Framework),
DKIM (Domain Key Identified Mails).

SPF

Via a TXT record in the DNS zone of the sender’s domain name, the idea is to authorize the IP addresses that can send emails using this domain name.

DKIM

This also works through a TXT record in the DNS zone of the sender’s domain name. DKIM contains a public key and a private key and, in addition to authenticating the domain name, it helps ensure the integrity of the message.

SENDING FREQUENCY

Sending frequency is an important criterion to take into account.
If you regularly send 10,000 emails but suddenly need to send 200,000, you’ll need to go through a preheating phase (warm-up).

Also, ISPs (Orange, SFR, etc.), unlike webmails like Gmail, aren’t used to receiving a huge volume of emails all at once. They can therefore throttle emails (let through 1 every 30 seconds, for example) or, worse, put them in spam.