I wrote recently about the futility of trying to reach inbox zero . Since email expands to fill the available space, the best approach is to plan in important things first–creative work, mentoring, dreaming–and then let email fill in around the edges.

But even if you agree with that philosophy, there are practical considerations. What if most during-the-day communication in your office occurs via email? And what if responding to emails actually is a big part of your job? Are there smart ways to check email in those cases?

This came up recently for me when a woman who works in compliance showed me her schedule. Her time sheet was covered in email, 30 minutes at a time every 60 to 120 minutes during the day. At first we joked about this “problem”–but as we got to talking more about the nature of her job, I realized she had figured out an extremely smart way to be accessible, yet also get things done.

Most office workers claim they’d like to spend less time on email, and most of us also know that the usual advice is to check our inboxes less frequently. Time management expert Julie Morgenstern told us years ago to never check email in the morning, and productivity guru Tim Ferriss argued for checking email twice a day, at noon and 4 p.m. in the 4-Hour Workweek.

Some of us can do this. I don’t have colleagues emailing me at 10 a.m. to schedule an 11:30 meeting with the expectation that I will see the invite. My job also doesn’t involve answering email as a primary function. In this woman’s case, people were sending her questions and her job was to answer quickly so people could go about their work.

What she’d realized is that even if you do have to be on email constantly, you are best off designating email and non-email times, even within the hour. The time sheets I give people to fill out contain 30-minute blocks, and the reason this woman’s time log featured so much email is that she was spending a full 30 minutes on email, unlike most people, who sneak checks constantly. She’d do email for 30 minutes, and then spend 30 to 60 minutes on something else. She would give the quick responses necessary, and then she would step away from her inbox and go work on a memo or review a report for 30 to 60 minutes. Then she would give her inbox her full attention for another half an hour, and so forth.

Here’s the reason to do this: 30 to 60 minutes isn’t that long to wait for a response, even to an urgent email. People are sometimes in meetings that don’t allow for responses. Or they’re grabbing coffee, talking with someone, driving somewhere, or they’re in the bathroom. There is little marginal benefit gained in guaranteeing a response within 10 minutes vs. 30.