This is a Secured Letter icon. We've made it in iOS style, first introduced in iOS version 7 and supported in all later releases up until now (at least iOS 11). This style is based on thin two-pixel lines and is optimized for 50x50 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 12,600 icons, all in the same style and quality.
We've received the idea on February 15, 2013 and created the icons on February 24, 2013
The black Mail Icons are great but sometimes the Otline style looks better. So I would like to have your Mail Icons in an outline Version also.
Story about Secured Letter Icon
Annoying your friends has never been easier. Don't just send them a message, send them a message with a free downloadable message icon, an empty, digital envelope, illustrated and designed to piss the other person off.
Of course, pissing someone off isn't the only thing you can do with it.
Put it next to your contact information on your website, letting people know where they can reach you, obviously.
Design a logo for a messaging app—even though millions of those already exist, I can't see how you can make that possible.
Print out the icon and leave it in your mailbox, let the postman figure it out, oh wait, it might piss him off.