task management software?

Hi folks,
I'm hoping to find out how other companies manage queues with many requests (via email), changing priorities, quick turnarounds and multiple team members. The reason I ask is because our queue changes almost hourly and more often than not, junior team members rarely know when or how to change gears and prioritize what’s more important unless specifically asked to stop what they're doing and work on what’s now on the top of the queue. As things get busier, I expect this will only get more complex and frustrating and things will fall through the cracks.

Are there software tools that would help manage this? We do use JIRA for requests that involve other teams (engineering), but sales doesn't use it and since our sales team is not in the office giving them VPN access only so they can use JIRA is not ideal. The answer I’m looking for is something to manage tasks from the team with the short and quick turnarounds. Any advice or insight on what others like and use?