****IGNORE THIS****
Due to an extremely annoying lack in Mail.app, the critical “Date last viewed/Not in the last...” filter simply doesn't work. Sorry.
The Box: How to keep a clean Inbox (OSX Lion)
It is very common to use the Inbox as a To Do list or reminder system. Once a message has been dealt with, it is either deleted or archived into a folder somewhere. The problem is that sometimes you can get behind--sometimes very behind--and the Inbox gets filled with messages that you promise yourself that you will deal with.
Here is an approach to dealing with this problem using Smart Mailboxes and the seven Message Flags. I implemented it on Lion, but it will probably work on most OS/X versions.
HOW TO SET IT UP
First, although the underlying interpreter is apparently capable of dealing with complicated rule systems for Smart Mailboxes, the user interface is not. In particular, there is no direct way to deal with situations like (X and Y) or (A and B). The indirect way of dealing with this is to create a Smart Mailbox XY that contains all messages meeting criteria X and Y and a second one AB with messages meeting criteria A and B. Then the whole thing can be represented by a third Smart Mailbox XYAB meeting XY or AB. In order to make this less busy, we will create a Smart Mailbox Folder and call it “zzz” so it will sleep peacefully at the end of the list of Smart Mailboxes.
Second, we will create a whole set of individual Smart Mailboxes and move them into zzz. The list is:
BoxToday (red)Box1day (orange)Box2day (yellow)Box3day (green)Box1week (blue)Box2week (purple)BoxAnyFlag (gray)BoxUnreadBoxOldTMP
These will contain rules such that the message will be in the Smart Mailbox if it has been flagged with the color indicated and if has not been read in the number of days or weeks indicated (BoxToday just depends on their being a red flag). For example Box2day has two conditions: Date Last viewed is not in the last 2 days; Message has Flag Yellow. BoxAnyFlag will always apply if any flag is set and if the message has not been read in a month. BoxUnread applies to all unread messages. Note that I chose the lags (0-1-2-3 day, 1-2 week, 1 month) arbitrarily, based on the notion that you'll want to push things back a short time more often than a long time, and that a monthly review of pushed-away mails is about right. But these can be set to whatever you want—for example, 0-1-2-3-4-5-6 days plus weekly reviews of unread and _TMP would also be perfectly logical, and there are other possibilities as well. Note that the colors are assigned an increasing lag as a function of their position in the flag menu button (red to gray).
Next, create a Smart Mailbox called Box. Unlike the others, it will apply if *any* rule applies. The rules it contains are “Message is in Mailbox X”, where X is all of the above Smart Mailboxes, plus Inbox (the common inbox for all accounts). Do not move this Smart Mailbox into the zzz folder. However, you should drag it up into the shortcut row along with Inbox, Drafts, Sent, and so on. It will stick up there for easy access.
Create a regular mailbox called _TMP and put it somewhere convenient. This will be used to contain miscellaneous messages that will not be archived but that you must deal with in the future. It may be convenient to add this as a shortcut next to Box. Be careful not to let the _TMP folder contain messages without flags. If you delete the flag, also delete (or refile) the message. Note that the BoxOldTMP Smart Mailbox will include any message in _TMP that hasn't been read in a month or more.
Optionally go into the View>Message Attributes menubar item and make sure that Mailbox is checked. This is very useful when looking in the Box because it will show you where each message is currently stored. You might also check either Date Sent or Date Received; this will help you distinguish old, recycled messages from new ones. Also, it is critical that Flags is checked here.
HOW TO USE IT
Once you have the infrastructure set up, you should click on the Box shortcut. You will see all of your current Inbox contents plus probably a bunch of old unread messages, and perhaps some previously flagged message. You *must* go through these, weeding out stuff you don't want, filing things that have been dealt with, and flagging and filing everything else. At the end, you will have an empty Inbox and no unread messages anywhere. If you come across a message you want to deal with but not file, put it into the _TMP folder, that's what it's for.
Now, instead of looking in the Inbox for new mail, look at Box. When a message arrives in the Box, either:
Deal with it, remove its flag if any, and delete itDeal with it, remove its flag if any, and file itFlag it with a (different) priority and file it
But never leave it in the Inbox. Note that when you flag a message with a Red flag, it will always show in the Box, regardless of whether it was filed. Similarly, after a day has passed, a message flagged with an Orange flag will show again, but will go away once you have looked at it again. Any message with a flag will show back up at least once a month.
It is also useful to add a few other shortcuts to the top of the window, for example, the current year's receipts folder (i.e., receipts2012). The shortcuts are especially useful in that in Lion, the mailbox hierarchy can remain hidden most of the time.
THE BUILT-IN FLAGGED FOLDER
There is a standard “Flagged” smart folder that you can use to look at all flagged messages if you forget where you put one. Note that this will show flagged messages that are in the trash, which is why you should remove the flag before deleting a previously flagged message.
AUTOMATIC FILING
In some cases, it is possible to file messages from certain recipients automatically with an incoming mail rule. This approach meshes extremely well with the Box approach. If you simply file such messages, then they will show up in the Box because they have not been read. However, if you “accidentally” read them (while browsing in Box) then they will not show up again. To help with this, you could also have the rule give them a flag, for example the Red or Orange flag, to make sure you see it.
USING iCal
In some cases, you don't want to just push back an email to some rough time in the future, you must deal with it by a specific but far-off deadline. The Box method is not for that. Instead, file the message and then drag the message to a date and time in iCal. This will make the reminder part of your regular calendar system.
