The Welcome Letter is what walks you through the initial setup of your Comporium system.  This is where you have the first change to enable/disable notifications, name devices, and other options.  Most importantly, it's where you set your credentials for you system.  The Welcome Email is only valid for 7 days after your purchase.  If you need a new welcome email just let us know and we'll get one right out to you.  

Email:  support@comporium.com

If you're having trouble locating your Welcome Letter, be sure to check your SPAM folder.  The email will be from Comporium.