When you are doing your sort if there is a message that you can answer with a quick reply do it! That way it gets out of your inbox and is dealt with. If you get advertisements that you don't want to see immediately scroll down to the bottom of the message, find the tiny print that says UNSUBSCRIBE and unsubscribe from their list. Most vendors want you to be happy and will immediately take you off of their list if you only ask. If you do it right away you can keep your inbox from filling up with unsolicited ads. You will have to keep up with it since there are always new ones, but it is easy if you do one at a time.
- Create folders and for the messages that you may want to find again have a good system of saving them. Archive or delete all the rest of your mail so that your inbox can be fairly empty after it has been read. In most programs when you create a new folder it is on the left side and you can just drag messages from the right and drop them into the correct folder.
- If you use Gmail I have found that the search function works really well. What I do is to archive almost all of my read messages. They are compressed then and saved in a very small format, so my mailbox does not get jammed. When I need something I just do a search and so far it is finding what I need!
Sometimes you have time to write something, but do not want to send it right away. In Outlook you can choose Options > Delay Delivery > Do not deliver before. In Gmail there is an add on called Boomerang that allows you to designate when you want a certain email sent.