Email Client CSS & HTML Support
Discover which CSS and HTML features are supported by your favorite email clients. Select a client below to see detailed compatibility information and feature support.
AOL
Apple Mail
Fastmail
Free.fr
Gmail
GMX
Hey
IONOS 1&1
La Poste
Mail.ru
Orange Mail
Outlook
ProtonMail
Rainloop
Samsung Email
SFR
T-Online
Thunderbird
Web.de
WP.pl
Yahoo Mail
All Email Clients
AOL
AOL Mail is a free email service. Our support tracking shows feature compatibility across desktop and mobile platforms.
Apple Mail
Apple Mail is the default email client on macOS and iOS devices. Check CSS and HTML support across different versions.
Fastmail
Fastmail is a privacy-focused email service with strong standards compliance. See which modern CSS features it supports.
Free.fr
Free.fr is a French email provider. Review its support for CSS, HTML, and email formatting features.
Gmail
Gmail is one of the most popular email clients. Gmail supports many modern CSS features on desktop, web, mobile, and through apps.
GMX
GMX is an email provider with users worldwide. Check CSS feature support across its platforms.
Hey
Hey is a modern email service focused on organization. See which advanced email formatting features it supports.
IONOS 1&1
IONOS 1&1 is a German hosting and email provider. Review feature support and compatibility.
La Poste
La Poste is the French postal service email provider. Check its CSS and HTML support coverage.
Mail.ru
Mail.ru is a major email provider in Russia and surrounding countries. View supported CSS and formatting features.
Orange Mail
Orange Mail is the email service from Orange, a major European telecommunications company. See CSS feature compatibility.
Outlook
Outlook includes Microsoft Outlook desktop clients and Outlook web versions. Limited CSS support compared to modern web email.
ProtonMail
ProtonMail is a privacy-focused email service with strong encryption. See which CSS and HTML features it supports.
Rainloop
Rainloop is an open-source webmail solution. Review CSS and HTML feature compatibility.
Samsung Email
Samsung Email is the default email client on Samsung mobile devices. Check CSS support.
SFR
SFR is a French telecommunications company email provider. View supported email formatting features.
T-Online
T-Online is a major German ISP and email provider. Check CSS and HTML support.
Thunderbird
Thunderbird is Mozilla's open-source desktop email client. Review CSS and HTML support across versions.
Web.de
Web.de is a German email provider. See supported CSS features and compatibility.
WP.pl
WP.pl is a major Polish email and web portal. Check CSS and HTML formatting support.
Yahoo Mail
Yahoo Mail is a widely used email service. Yahoo Mail supports many CSS features on desktop and mobile platforms.
About This Resource
This guide provides comprehensive CSS and HTML feature support information for 21 major email clients. Data is sourced from email testing and compatibility research. Support levels include full support (✓), partial support, and no support (✗).