Once you set up your plans as needed, a hyperlink titled "View Offered Plans" will automatically be activated and added to your SphereMail account login page, where all your visitors will be able to click and view your offered plans and services and subscribe to the one they desire: 

You can also use this page's URL to embed it into your website to use for marketing purposes.

Note: The hyperlink will only be activated if the operator has at least one visible plan; if all offered plans are hidden or set to zero fees, the hyperlink will be hidden by default.