outline
Sets a line outside of the element’s border.
Outlook
Windows
2007
2010
2013
2016
2019
Windows Mail
2022-03
macOS
16.60
16.80
Outlook.com
2022-03
2024-01
iOS
2022-03
Android
2022-03
Samsung Email
Android
6.0
Mozilla Thunderbird
macOS
78.14
Fastmail
Desktop Webmail
2022-03
HEY
Desktop Webmail
2022-03
LaPoste.net
Desktop Webmail
2022-03
1&1
Desktop Webmail
2022-06
Android
2022-06
Mail.ru
Desktop Webmail
2022-03
WP.pl
Desktop Webmail
2025-09
Free.fr
Desktop Webmail
2022-12
T-online.de
Desktop Webmail
2022-12