You can email directly from within this program, provided you have an SMTP server. To do this, set up your email settings: Tools->Network->Email settings

Note that if you’re using Gmail, you need to change a setting to allow less secure apps, since this program needs your Gmail password to send emails (it doesn’t use Gmail’s API to do it in a way that doesn’t give this program access to your password). You do this at your own risk. However, you’re free to analyze the source code to determine whether or not it’s safe.
        
Then, in an open tab (it doesn’t matter if the tab is saved), format your email as follows:

to: email addresses delimited by commas or semi-colons with optional spaces after them
subject: your email subject
attachments: Attachments are optional, but put a single path to a file or directory here. You can optionally put attachment, att, or a instead of attachments.
att: A second attachment (optional, of course; you can do as many attachments as your email provider will allow).
a: A third attachment

Write your message here.

Press Ctrl+comma to send (or Tools->Network->Send document as email).

Okay, so now you may be wondering about why you can put directory paths as attachments. If you do so, it will allow you to compress it into one file, and send that file as an attachment. The file is saved in a temporary directory, which is deleted when your email is sent.

You can only add one attachment per line because this makes it simpler to send files that contain commas, semi-colons and such.

Instead of writing in the recipients, subject and attachments in the open tab, you may do so via the Network menu instead. When you do this, you’ll find that the program remembered your previous recipients, subject, and attachments (which you may keep or change).

Attachments are not arranged in any particular order.

If you don’t want to manually write out the filepaths for your attachments, use Tools->Insert filepath to select a file and output its filepath into the editor. This won’t work for directories (so just select a file in the directory and then take it off the outputted path—or some such).

Note that whitespace is stripped from the beginning and end of your message body.