External users prompted to join team when shared a file

Dirty practice from Dropbox to prompt a recipient of a shared file to be asked to join your team. This prompt confuses the recipient of the file who requests to join the team and therefore Dropbox gains another paid user. 

This user (from another company) if added to the team by an overworked I.T. dept who isn't paying attention, then gains access to the company files.

Please re-work your prompt system and remove the option to request access to join the team. We can add members to the team from the admin console and this is the most secure way to do this.

This fault is obviously a great way for Dropbox to gain 'accidental' paid users at the expense of security. I receive a few of these emails each month and each time it's just Dropbox testing my intelligence again to see if I will accidentally add a totally random person to access our company files by mistake. This is absolutely not secure file storage and is designed to be misleading. It is frustrating that Dropbox is actively phishing.

Disabling the ability of a user to request to join a team (from outside your company) would resolve this. It is hard to imagine a scenario where you would want to add (and pay for) an external user to your team. If you did need this feature, it would be a deliberate action and the cost involved would need to be approved (an ongoing subscription - the worst kind of cost). Email requests from external users would of course be ignored and make no impact on the purchase of the license. 

The current short term fix i can suggest is just setting Dropbox emails to block/spam/autodelete. Thanks for reading this far.