Technical Tip: How to not allow users to add additional accounts on Gmail

[jhelder]

Description	This article describes a web filter use case to prevent users from adding more email accounts on Gmail. This is useful in scenarios where a company email has been set up and it is undesirable for users to add other accounts, such as personal accounts.
Scope	Any version of FortiOS.
Solution	To achieve this, use a web filter with static URLs and deep inspection. Deep inspection is mandatory because the CA for Google email is always the same and it is necessary to inspect the traffic to verify the URL. In the firewall policy, under the web filter profile, create a new entry in the Static URL filter and define the URL for Gmail ('accounts.google.com'). This is the address that Google uses to add a new account. The type for this filter can be set to 'Simple', and the action should be 'Block'. Next, define the DIP in the firewall policy: If a user tries to add any additional account on Gmail, they will be shown the block page: