I have had a Galaxy S3 for some 3 years and I have recently noticed that I have in excess of 45,000 emails in the standard email's trash folder.
I have tried selecting the trash folder and then using the "delete all" option but the speed of deletes is staggeringly slow, one every five to ten seconds.
It is synchronised with an Office365 account, and I have checked on the server side to see if the same folder exists but it doesn't, it is only on the phone. (Note that this is the standard email app, it is not Gmail or anything similar).
Is there some quick way to empty the email trash folder, either through a file app, or a third party app?