I need to delete certain Gmail messages older than n days (I can get the whole set though a search string). I know this is not possible directly within Gmail (see for instance this question) so I am looking for a webapp which could handle such activities on my account (and, generally, similar housekeeping tasks).
An automated solution that would actively mark messages as read when they reach a specified age is the desired solution. Is there a way to accomplish this through Gmail filters and some syntax? Are there any apps, scripts, etc. that would help?