I'm sure this differs by individual, but for me, processing an inbox is mainly about getting stuff out of the inbox and parked for the next step--I very, very rarely DO anything at all while processing an inbox. So as I glance at emails, I scribble actions (I say "scribble" because I've very recently gone to paper):
- Respond: Apps using Java versus Javascript, email 6/4, Smith.
- Respond: Oracle requirements request, email 6/5, Jones.
- Respond: Privilege request, email 6/5, Andrews.
- Read: PDF from Foster, email 6/4, requesting comments ASAP.
Writing each action takes less than thirty seconds and, more importantly, it doesn't take me out of the "processing inbox" flow.
I don't really even believe in the two minute rule, because the cost of breaking my own flow is far more than two minutes. I tend to use it only when there's some other potential loss--for example, let's say I don't do privilege requests, I know they take forever, and I know Andrews is about to go on vacation, so he's about to lose two weeks that could be applied to that "forever". In that case, I'll spend sixty seconds responding to tell Andrew that I'm the wrong person, and maybe also warning him to warn his manager to check RequestApprovalAppThing every few days because only Andrews, not his manager, will get the notification email, and Andrews will be on the beach.
My goal is to get the processing out of the way as quickly as possible, so that I know what the resulting basket of tasks look like. After that, I have a clearer view of my work and can decide what to do--work on the Gadget project across all its contexts, or pick one content and do all my reading or all my quick information requests, or write an email about a problem that has become apparent based on several emails, or...whatever.
So after I process the above, I might note the "requesting comments ASAP", and I might therefore decide to do my reading backlog today instead of, oh, next Wednesday as I'd planned. After entering Foster's request and noting the hysterical tone of it, I might add an action, or a meeting-with-myself calendar entry:
- META: Prioritize doing To Read, per Foster's 6/4 request.
Now, this does mean that I effectively have more than one level of processing. I may hurriedly read an email, classify it as "information request", note it in an action, and thus get it out of my inbox. Then later I may process all my information request tasks, and end up expanding a few of them into a few actions. I'm OK with that double processing. I have, for a long time, utterly rejected the "only handle it once" philosophy.