For Automation Rule Conditions It seems that it has limited support for complex conditions.
The plan was if the requester is coming from an external email domain, the incident ticket created should be assigned to a certain site.
However, looking for a way to setup the conditions as:
Field: Requester --- Element: Email Domain --- is not equal to --- (internal email domain)
which tells that if all other email domain that is not equal to the internal email domain, assign the incident to a specific site.
Currently for the Automation rules condition it seems that it is limited to setting up all external domain value as the condition is only limited to "is equal to", having to manually add the condition for each external email domain which is difficult to configure. For the Service desk is currently setup to accept all domains.