Integrated Alerting: Field validation in Email and Slack tabs when updating settings

3. In http://3.142.238.136/graph/settings/communication there’s no validation of email addresses/hostnames etc. any string is accepted

4. Same for Slack

https://docs.google.com/document/d/1a8cznJ0MaC4bGXFZWWvvqvgA4xN0s1IjOI73kxvYgMY/edit