Can I query Salesforce Queue and can I do it using the metadata or tooling APIs? Looking to quickly access this data from Salesforce inspector, also looking to see if there is a way to check if a queue triggered an email, not using email logs...
You can query queues with a normal SOQL call, no metadata/tooling API necessary. The objects related to queues are actually Group and GroupMember.
Queues do not generate emails, users do, so there's no way to specifically check if an email came from a queue (e.g. because a record was placed in the queue).
The queue query would look like this:
SELECT Id, Name FROM Group WHERE Type = 'Queue'