Please note that if you make use of the $!group0/$!group1/etc. placeholder (i.e. a capture group reference) in your JQL condition, it must be put between double quotes, e.g. as ”$!group0”.
If you need to combine various needs, which cannot be expressed in a single lookup (or with the linear combination of the subsequent lookups), you need to create different Mail Handlers to cover those (mutually exclusive) logical rules.If you make use of the issue key in your JQL condition (e.g. issuekey = “$!group1“), the JQL validator may not discover actual problems with the expression provided, since validation errors on issue keys needed to be suppressed, as Jira returns an error message by default, if the query is run for a non-existing issue.