If tracking is switched on then links in emails will automatically be tracked. When a link has been visited it will get a green background and mouseing over the link will show the number of times that link has been visited.


Links have to be inserted into the compose box using the Gmail 'Insert Link':
(this correctly formats the link using '<a href' etc):

Attachment tracking is optional and allows you to see when an attachment was downloaded,
a) Password protect the file (optional) - useful to ensure only the recipient (with the password) can download it.
b) Disable the download, you can switch on or off the ability to download.
c) Delete the attachment so it can never be downloaded.

You may not want to track an attachment so when you click on "Attach files" or "Insert files from Drive" you get a choice:

Default is the normal Gmail action for attachments.
If you select to use passwords it will present you with a password submission box for each person you are emailing.
You write these passwords down somewhere... and then tell the recipient by text, phone etc what their password is.
(Don't put the password in the email!)

When you've submitted the passwords you will see the Drive or files box. Select a file and a link to your file will be created and inserted in your email. Image below shows 2 files to be sent:

When the recipient clicks on the attachment link and there was no password required, the file will immediately download.
If a password was required, they will have to enter the correct password to download:

In your sent email, tracked attachments appear like this, attachments with a green high-lite have been downloaded, placeing your mouse over the link shows the number of times it has been downloaded.


If you want to disable the download, click on the grey cross on the right of attachment link, this will prevent any further downloads.
Mouseing over the grey cross will confirm it's current status - whether downloads have been disabled or not.