When tickets are created by email, they use the subject line as the ticket summary.  This isn't always a great option:

• Sometimes, we ask people to put certain keywords in the subject or at the beginning of the subject so that we route their ticket to the right place - like 'ORDER FEEDBACK' or 'STRIPE BUG' - but then this clogs up the ticket display and makes all the tickets look the same. 
• Ticket titles often include Re:, Fwd:, and all their permutations
• There are always those repeat offenders who constantly litter their ticket titles with "URGENT", "IMPORTANT", "NEED THIS TODAY", "SOS", "EMERGENCY", etc - and these words can trigger people to either do work out of order (basically allowing the users to dictate our priorities for us, when often an individual's priorities don't necessarily match the needs of the business) or, on the flip side, ignore tickets out of spite (hey, it happens).

It would be helpful to have a filter where we could enter these strings and have them stripped from the summary.  De-capitalizing all summaries automatically would also be nice also less important.   It might be easiest to simply provide an option to add regex substitutions that are applied (and you can either substitute with nothing or with, for example, lowercased text).