PNG ICO ICNS MORE
Desktop apps
Smooth
Shiny Icon Set
send, mail, envelope
WhiteSmoke
64x64
Application Pack Volume 01
Email, mail, envelope
128x128
PNG MORE
Social media
Social and Web Icons v2
Email, envelope, mail
46x46
Mixed
Some icons
envelope, Email
80x80
UI
Snowish
mail, Email, envelope
Files & folders
iD
newsletter, Email, mail
PNG ICO MORE
Social and web icons
mail, envelope
Ultimate Gnome
mark, mail, Check
256x256
Email, envelope, open
48x48
Network & communications
Oxygen