In server configuration -> email domain name validation is not done.
Steps to Reproduce:
Login to zanata using admin.
Click on admin tab from left panel.
Click on server configuration.
Enter anything in email domain name field. e.g abcd,1223 without .com
Observer that no any error message shown.
Click on save.
Observe the behavior.
Email Domain Name filed accepts anything as a domain name.
Its accepts numbers also.
Its accepts string without .com or any domain.
Email Domain Name validation should be done proper.
It should show proper error message. eg. after entering only string it should show "please enter proper domain name" and after entering numbers it should show "numbers are not allowed here"
Attached screen captured for more ref.
Fedora 25 + Firefox 50 (64 bit)