To share files from Finder in Max OS X is now possible with Airmail’s Extension
There are two sharing extensions:

Airmail Composer
Airmail Share
We will discuss them in-depth shortly.

First, it is necessary to enable these extensions

Enable Airmail Share Extensions

Click on the Apple  in the menu bar and select System Preferences
In the 3rd row, click on the Extensions icon.
In the left column click on Share Menu.
Select the Airmail Composer and Airmail Share extension in the extension list.


Close Extensions and System Preferences windows.

The Airmail Share extensions are now enabled.

Extension Types

Airmail Composer Extension

In App Composer

The Airmail Composer extension allows sharing of documents and files as attachment by opening a mail
composer window without leaving the active application.

As seen in the image below, the document is attached when choosing the Airmail Composer extension.

Continue composing the email as normal and click on send.

Airmail Share Extension:

The Airmail Share Extension, once clicked, opens the standard composer window of Airmail, effectively
leaving the active application and going to Airmail app, where messages can be composed as standard.

Using Share Extensions in Finder

The Airmail Extensions are available anywhere on the Mac where you can see see the Share icon or on the
right click menu in Finder.

Using the Share Icon Menu

Located the Share icon in Finder or any other app that supports it.
Click on it to open the Sharing Menu.
Click to chose which of the Airmail Extension to use.
The file that was shared will be added to a new mail composer window as an attached file.
Compose the email as normal and click send.

Published on: 01 / 12 / 2019