Web-CAT emails are flagged as spam by students' email providers

I have established Web-CAT accounts for all of my students. However, Web-CAT sends out the username and password credentials by email, and my students' email providers are completely disregarding these messages as spam.

I have attempted to query the Web-CAT database for the passwords, but they are stored as hashes.

Is there any other procedure I can follow to obtain my students' passwords?