Introduction
The aim of this article is to inform users of the best practices to apply when creating HTML for emailing. A series of recommendations relating to several components of an email are listed in this article.
Description
Particular attention is paid to the following elements:
- The email subject
- HTML format
- Text format
- The images
Email subject
| Description of the element | Our recommendation |
| Use of capital letters | We do not recommend using several capital letters in a row. |
| Use of emoji(s) ☀️ |
Not recommended to use several emojis in the subject line. |
| Use of "spam words" (Free, hurry up!...) |
Not recommended because stress timing, exclusive offers and benefits are often filtered out by ISPs and web browsers. A message will be displayed if spam words are detected in the subject line. |
| Use of several "!!!" exclamations | Not recommended as this is considered stress timing and is often used by spammers |
| Combination of the above elements (capitals, emoji, spam words, exclamation) | Not recommended, as they are often used by spammers. |
HTML format
| Description of the element | Our recommendation |
| Use of responsive design | Recommended |
| HTML width |
Width between 600 and 800 pixels |
| Width of responsive version |
Maximum width 320 pixels |
| Maximum HTML size | 102kb (Gmail will cut off the email if the HTML exceeds 102kb) |
| Mirror page | Recommended to make reading easier for the user |
| Unsubscribe link | Recommended to have at least one clear and concise unsubscribe link at the top of the email to encourage users to unsubscribe from marketing communications. |
| Use of a text version | Not compulsory, but useful for increasing the image/text ratio |
| Use of Javascript / Flash | Not recommended |
| Use of a background colour attribute in the body tag |
Not recommended to use a background colour attribute in the HTML body tag for all webmails and ISPs combined (negative impact in particular for orange.fr and laposte.net) |
Text format
| Description of the element | Our recommendation |
| Font size | It is not recommended to use several capital letters in a row. |
| Font colour |
It is not recommended to use several capital letters in a row. |
| Use of "spam words" (Free, hurry up!...) |
Not recommended because stress timing, exclusive offers and benefits are often filtered out by ISPs and web browsers. |
| Font | We recommend using the standard fonts available from ISPs and web browsers: Arial, Verdana, Georgia and Times New Roman. |
Image format
| Description of the element | Our recommendation |
| Image size | Between >0 and 500kb |
| Weight of a GIF |
Between >0 and 1mo |
| Total weight of images/GIFs used in HTML |
The lower the weight, the better the ISP's ability to load the email in the user's inbox. It is recommended to have a maximum of 1 GIF with a high weight out of all the images in the HTML. |
| ALT tag (text description given to an image) | Recommended. An ALT tag is required for all images. |
| Image hosting URL | All urls must begin with https |
Conclusion
There are several levers for action to optimise the deliverability of a mailing (reputation, infrastructure, database management), including the content of the email, which is the subject of this article. Despite the fact that these recommendations do not necessarily enable an email to reach the inbox, it is nevertheless necessary to apply these various recommendations in order to optimise deliverability in terms of content.