The email you use to login to Clio with is the one that is associated with you. If you send email to Clio from a different email address, it will be blocked as Spam - unless you add an Email Alias.
Click on your name at the top of the page and choose "Settings" and in the Personal section choose "Profile".
Select "Mail Drop Email Aliases" from the Profile options.
Here you'll find you will have the ability to add email addresses by clicking on "Add" and entering in the email.
Once you have saved the new information, you will see that email in the list of Email Aliases. Now when you send an email to Clio from that particular address, the email will be saved in Clio.