I keep it empty or I abandon ship.

Messy.

Not many questions in my inbox because only 2 people that I follow

I've only been here about 2 weeks. I'm well on my way to a cluttered mess though

I had to because they were up to 1109 and aint nobody got time fo'dat!

I just clear it out whenever I realise I've not done it in a while or when its full of crap from anonymous cowards.

My inbox holds most of the time only messages that date back a few days. Usually it gets empty through the course of the day.

Years.

mine is a hot stinky mess because I don't really delete questions unless I have absolutely no intention of answering them. I'm afraid I might delete a question that I'll want to answer in 6months

I tolerate an overstuffed inbox for a few weeks maybe, then I go on a cleaning fit and answer everything I have an answer for and purge everything else, then all is well for a few weeks until it's out of control again 👍

The oldest question in my inbox is probably older than you