Hellobee Boards

I file mine by project or program that I'm working on and then by subsequent issue. I do that for every year

I create folders based on project or subject of the e-mail. I only keep e-mails in my inbox that I still need to take action on. I use the category system in the inbox to group e-mails, so if I need to hold onto an email for awhile to remind me to do something later it goes in the red category, orange means I'm waiting for a response on the e-mail, etc. I then sort my inbox by category so everything is grouped together.

No system here. They just all sit in one place and I just search for what I need.

Emails for specific projects get their own folder. I also have a folder for "Saved Communications"- these are emails that my company sends out with important info that I might need to reference later but that don't pertain to a specific job function of mine. I delete all but the last email in a string if communications. I also delete all emails pertaining to the communication once the conversation is over or whatever it is we were talking about is taken care of.
I have 6 emails in my main inbox right now. It stresses me out if there are more than like, 15 at any given time.

I save them into client folders. My work has a 30 day email retention policy so if they don't get saved then they get deleted. It's a legal thing.

Once an email is no longer an action item it gets filed or deleted. Most of my emails have to be saved for file retention reasons. I have about 85 different folders that emails get saved in depending on the sender/subject. I then archive old emails about twice per year to open up storage space in my email. Ideally, at the end of any given day, my inbox is empty.