To make long story short: you write your email as normal, attach files as normal, then use the Filemail add-in to encrypt and upload the attachments. Filemail inserts a secure download link into your email, and you send the email from Outlook. The recipient opens the link, enters the encryption key, and downloads the files in their browser.
What the add-in does
When you use Send encrypted, the add-in will:
Detect the files attached to your Outlook email.
Ask you to enter an encryption key.
Encrypt and upload the files to Filemail.
Remove the unencrypted files from the Outlook email.
Insert a Filemail download link into the email.
Let you send the email normally from Outlook.
The email itself is still sent by Outlook. Filemail only handles the encrypted file transfer.
When to use it
Use the Filemail Outlook Add-in when you want to:
Send sensitive attachments more securely.
Avoid sending the actual files as regular email attachments.
Give recipients a download link instead of email attachments.
Control expiry and download notifications.
Send larger files that might get rejected by recipient.
For more information on how to use the add-in, see Filemail Outlook Add-in: Getting started. For detailed explanations of available transfer settings, see Filemail Outlook Add-in: Settings.