Rules I follow for emails
Rules to follow for emails in ServiceNow.
Actively discourage the use of Inbound Email as a mechanism for ticket creation. It should only be used when the sending party is a robot. Over time, the conditions desired by your stakeholders, and the propensity for user input error will make inbound email a horrific mess. Its also like Pandora's Box. Once you tell users they can email into ServiceNow, they'll never stop. I force stakeholders to sign off to knowing about a 30% failure rate if they want inbound email processing. -- rfedoruk
Above is a diagram from this docs page.