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Proceedings of BCS HCI 2013 - The
Internet of Things XXVII, Uxbridge, UK
How to Manage Your Inbox:
Is a Once a Day Strategy Best?
Adam Bradley1 Duncan P. Brumby1* Anna L. Cox1 Jon Bird2
1UCL Interaction Centre 2Department of Computing
University College London City University London
London WC1E 6BT UK London EC1V 0HB UK
*Brumby@cs.ucl.ac.uk
Many people are overloaded by the amount of email they receive. Because of this, a considerable
amount of time can be spent every day managing one’s inbox. Previous work has shown that
people adopt different strategies for managing their inbox. However, there has been little work
examining how the choice of email management strategy impacts the total time that one gives to
email activities each day. In the current study seven academics spent one week trying out different
email management strategies: either a once-a-day strategy or a frequent strategy. Data on the
amount of time spent managing email and subjective feelings towards each strategy were
gathered. Results suggest that a once a day email management strategy may be effective in
reducing the total time spent dealing with email.
Email overload, email strategies, personal informatics, work-life balance.
1. INTRODUCTION
Email is a ubiquitous form of communication. It is
the second most widely used method of
communication in business and academic
institutions, after talking face to face (Crystal,
2001). There are many benefits to using email as a
communication tool: it is fast, low cost, works
across long distances, and is asynchronous. It can
also support group messaging threads, mailing lists
and task management for many users (Whittaker,
Bellotti, & Gwizdka, 2006).
There are drawbacks to email – many people
receive more messages than they can easily
manage. They find themselves in a situation where
regardless of the amount of time they spend
managing their inbox they are unable to keep on
top of it. This causes many important emails to be
buried amongst less important ones. For some this
is a significant source of stress (Barley, Meyerson,
& Grodal, 2011). Furthermore, time spent
managing email can be distracting and impact
negatively on other important activities (Boswell &
Olsen-Buchanan, 2007).
In their seminal paper, Whittaker and Sidner (1996)
identified several strategies that people use to
manage their inbox. These included “no filers”,
people who never managed their inbox, “frequent
filers”, people who manage their inbox daily, and
“spring cleaners”, people who manage their inbox
intermittently (every 1-3 months). Surprisingly,
since this seminal paper was published it is still not
clear which of these strategies is best.
We examined whether using different email
management strategies changes the total time that
is spent on email. By recording the amount of time
people spend on email using different strategies,
we attempt to identify which strategy is the most
efficient. We assume that the most efficient
strategy is the one that requires users to spend the
least amount of time in order to manage their email
inbox. The two email management strategies that
we investigate are modifications of the “frequent
filing” and “spring cleaning” strategies.
University academics were recruited as participants
because they tend to receive a high volume of
email everyday. They were required to spend a
week as “frequent filers” and a week as “spring
cleaners”. As “frequent filers”, participants
processed email (by responding, filing or deleting it)
throughout the day. This strategy will be referred to
as the “frequent” email management strategy. As
“spring cleaners”, participants attempted to leave
as much of their email processing as possible to
single session each day. This strategy will be
referred to as the “once a day” email management
strategy. The amount of time spent on email in
each condition was recorded using a commercially
available software tool called Rescue Time
(www.rescuetime.com). This software runs in the
background on the participant’s computer, tracking
the time they spend actively using a specific
How to manage your inbox: is a once a day strategy best?
Bradley ● Brumby ● Cox ● Bird
application or website. The participant’s subjective
feelings about each strategy were also recorded.
In the following section we review work on email
overload, email related stress and the cost of task
switching due to email. As will become clear, a
once a day email management strategy should be
better than a frequent checking strategy.
2. RELATED WORK
2.1 How do people manage email?
Whittaker and Sidner (1996) investigated how
people use email in an office environment. They
identified two main issues that users had with
email: (1) they struggled to read and respond to
emails in a timely manner; and (2) they had
difficulty retrieving information from old emails that
were needed at a later time. Both of these issues
were due to users receiving emails at a greater rate
than they could deal with them. These problems
were found to cause reduced responsiveness to
emails and important information being lost
amongst users’ inboxes.
Whittaker and Sidner (1996) identified three distinct
email management strategies. These have been
referred to as no filers, spring cleaners and
frequent filers. No filers tend not to file their emails
but instead let them accumulate in the inbox.
Spring cleaners manage their inbox intermittently
every few months. They experience ‘tidy’ inboxes
for short periods after a clean up but generally have
overloaded inboxes. In contrast, frequent filers
dedicate time to keeping their inbox as empty as
possible by filing and deleting emails on at least a
daily basis. This results in a small and well-
organised inbox containing predominantly unread
messages.
While previous research has attempted to reveal
the strategies users adopt in order to manage their
email inbox, no research has investigated which, if
any, of these strategies is best. Although the
amount of time spent on email is a key factor in
assessing what makes an email strategy better or
worse, it is also important that an email strategy
decreases the amount of stress a user experiences
due to their email inbox.
2.2 The cost of frequent email checking
One way to assess the effectiveness of an email
strategy is in terms of how distracting it is. If a
strategy requires users to frequently switch from
their current activity to manage their email inbox
then it is likely that the user will be less productive
in completing their main task. For instance, Venolia
Dabbish, Cadiz, and Gupta (2001) observed that
many people keep their email visible at least two-
thirds of the time during their work day, so as to be
able to regularly check on the status of their inbox.
Similarly, Jackson, Dawson and Wilson (2001)
found that many users check for new email every
five minutes. These checks were to assess whether
any new emails in their inbox required urgent
attention. However, very few emails are of such
high importance that they require immediate
attention. What then is the cost to the other on-
going activities that the person is engaged in?
It is well known that interruptions are disruptive and
take time to recover from. Although some
interruptions can be beneficial, for example they
can allow a user to gain relevant information to
their current task (Mark, González and Harris,
2005), in most cases interruptions are distracting
and reduce productivity (Perlow, 1999). Because
emails do not require immediate action and can be
ignored until a user has the free time available to
handle them, it is possible that they will be less
distracting than other forms of communication.
However, Jackson et al. (2001) found that 70% of
emails were reacted to within 6 seconds and 85%
within 2 minutes. Furthermore, each time email was
checked there was an average of 64 seconds taken
to return to the previous task. It has been
suggested that this estimate is actually
conservative and that users actually take many
minutes to return to their original task after
managing and responding to their emails
(González & Mark, 2004). This suggests that
frequently checking email can be very detrimental
to other on-going activities.
2.3 Email as a stressor
We are also interested in how people feel about
using each email management strategy. It is known
that people levels of stress increase with the time
spent on email (e.g., Barley et al., 2011). This is
because spending a lot of time on email can cause
an individual’s workday to be longer. Coupled with
this is the fact that people can continue to work on
email at home during periods that traditionally
would have been set aside for other activities
(Boswell & Olsen-Buchanan, 2007). Therefore if
one of the strategies used in the current study
results in participants spending less time on email,
then we might expect this strategy to reduce
feelings of overload and work-related stress.
2.4 Overview of the current study
The focus of the current study is to determine
whether a once a day email management strategy
is better than a frequent checking strategy. The
previous work discussed above suggests that there
should be several benefits to adopting a once a day
strategy. First, people should be more efficient in
processing their inbox. In particular, they should be
more likely to process all of the unread emails in
their inbox, rather than deferring the processing of
How to manage your inbox: is a once a day strategy best?
Bradley ● Brumby ● Cox ● Bird
some emails until later. Second, adopting a once a
day strategy should reduce the frequency with
which people interrupt themselves to check on their
email inbox. Finally, due to a decrease in the
frequency which individuals check their email, they
should feel less stressed due to email being less
intrusive into their lives throughout the day thus
enabling more time to be spent on other activities
uninterrupted.
There are also several potential issues with
adopting a once a day email strategy. First,
individuals might worry that this strategy will result
in them falling behind on their email. Second,
participants might find it stressful trying to process
all of their emails in a single session. Third, despite
email being an asynchronous method of
communication, many emails exchange information
that is highly time sensitive. Even a fast reply
merely acknowledging receiving an email is
sometimes preferred to a slow reply. These
problems raise questions of whether participants
will be capable of only checking their emails once a
day, how they will feel about this restriction being
placed on them, and what implications these
restrictions will have on their experience at work.
However, it should be noted that recent work by
Mark, Voida, & Cardello (2012) has shown that
people can survive without email and still complete
work activities – because they find other ways to
communicate.
To evaluate whether there are benefits to a
particular email management strategy we had a
group of busy university academics, all of who
received a lot of email every day, try and adopt a
once a day email management strategy for a week.
We had the same individuals also try and adopt a
frequent email management strategy for a week.
We were interested in whether this change in email
management strategy would have an effect on the
amount of time spent on email. We were also
interested in gathering subjective reports of how
people felt about each email management strategy.
3. METHOD
3.1 Participants
An opportunistic sample of seven (three female)
junior academics (1 x lecturer, 1 x research fellow,
5 x graduate research students) took part in the
study, with a mean age of 28 years (SD = 4.1,
range = 24 - 34).
All of the participants reported that they received a
large number of emails and that they felt that they
struggled to manage their inbox effectively. In
exchange for their participation, participants were
given feedback on which email management
strategy was more efficient for them as well as
information on how much time they were spending
on email during the course of the study.
3.3 Design
We gave instructions for participants to try and
adopt either a once a day or a frequent email
management strategy. For the once a day email
management strategy, participants were asked to
limit how often they checked their email inbox and
process most of their email in a single session each
day. We did also tell participants that they could
reply to urgent or important emails whenever they
needed to. For the frequent email management
strategy, participants were encouraged to
frequently check their email inbox throughout the
day and to process all emails as soon as possible –
with the explicit goal of maintaining a relatively
empty/low inbox.
We used a within-subjects design so that every
participant had to try and adopt each email
management strategy for a week. The order in
which each strategy was used was counter-
balanced across participants.
We were interested in whether participants
changed how frequently they checked email
depending on which strategy they were supposed
to be following. Assuming that there is a difference
in email behaviour, we wanted to find out which
strategy led to participants spending the least
amount of time on email over the week. We were
also interested in getting a general sense of how
participants felt about each email management
strategy.
3.2 Materials
We used a software tool called RescueTime
(www.rescuetime.com) to record how much time
participants spent on email. RescueTime records
the time that people spend actively using an
application on their computer, giving an hourly
breakdown of usage for each application. By using
RescueTime’s “white-list” feature, participants gave
the experimenter remote access to their usage data
for email applications and websites.
To get a sense of how participants felt about
following each email management strategy, a brief
questionnaire was developed and put on Survey
Monkey (www.surveymonkey.com). The questions
asked were: (1) How similar to your current email
strategy is the strategy used? (2) How easy was it
to adopt the strategy? (3) How strictly did you
follow the instructions of the strategy? (4) How long
do you think you spent on email compared to a
normal week? (5) How stressed did you feel by
email whilst using this strategy? (6) How distracted
did you feel by email whilst using this strategy? (7)
How well have you been able to manage your
inbox whilst using this strategy? Responses were
How to manage your inbox: is a once a day strategy best?
Bradley ● Brumby ● Cox ● Bird
given on a 9-point Likert scale, where higher valued
responses represent a stronger level of agreement
to the question.
3.4 Procedure
Participants were briefed about the experiment
before consenting to participate. An automated
email was sent to participants from the
experimenter that contained instructions explaining
how to install RescueTime on their computers.
Participants were asked to provide information on
which websites or programs they used for email
services so that the usage of these could be
tracked. They were also asked to provide a brief
summary of their current email management
strategies.
Participants spent a week using each of the two
email management strategies. While doing this,
participants were encouraged to keep a diary of
any difficulties, feelings or comments they had
about following the email management strategy. At
the end of each week, participants were prompted
to complete a brief online questionnaire about their
experience of following the email management
strategy. The following week, participants used the
alternate strategy and completed the same diaries
and questionnaires as they did for the first week.
4. RESULTS
If participants followed the instructions to change
their email management strategy from one week to
the next, then we would expect to see a change in
the number and duration of email sessions (that is,
each unique time that an email application or
website was used).
Participants clearly struggled to implement the
once a day strategy: the mean number of email
sessions per week was 25 (i.e., about 3.6 sessions
per day). However, there is evidence that the
participants were changing their email behaviour
across conditions because the mean number of
sessions in the frequent checking condition was 56
(i.e., 8 sessions per day).
Given that participants were checking email less
frequently when following the once a day strategy,
we next consider whether this brought about a
reduction in the amount of time spent on email
during the week. It was found that participants
spent fewer minutes on email over the course of
the week when following the once a day email
management strategy (M = 148.29 min, SD =
108.88 min) compared to the frequent email
management strategy (M = 256.71 min, SD =
237.65 min). Because of the small sample size
(N = 7) and high degree of variance in the amount
of time spent on email between participants, we
use a non-parametric Wilcoxon signed-rank test to
Table 1. Responses to questionnaire items after using
each email management strategy for a week (mean and
standard deviation). Responses are given on a 9-point
Likert scale, where higher valued responses represent a
stronger level of agreement to the question.
Questionnaire item
Strategy used
Z-Ratio
Once a
day
Frequent
How similar to your
current email strategy is
the strategy used?
7.7 (1.8)
2.7 (2.2)
2.21*
How easy was it to
adopt the strategy?
8.1 (0.4)
2.6 (2.4)
2.38*
How strictly did you
follow the instructions of
the strategy?
4.9 (2.0)
2.1 (1.3)
2.12*
How long do you think
you spent on email
compared to a normal
week?
5.0 (1.5)
4.9 (0.7)
0.11
How stressed did you
feel by email whilst
using this strategy?
5.4 (1.3)
4.7 (1.3)
0.00
How distracted did you
feel by email whilst
using this strategy?
5.7 (1.6)
5.6 (2.0)
0.92
How well have you been
able to manage your
inbox whilst using this
strategy?
5.1 (2.0)
5.1 (1.2)
0.17
Note *p<.05
test for statistical significance. Results show that
participants spent significantly less time on email
when following the once a day email management
strategy compared to the frequent email
management, Z = 2.20, p = .03.
Finally, we consider the questionnaire data. Table 1
shows the mean responses given by participants to
each question after using each email management
strategy. A series of Wilcoxon signed-rank tests
were performed to see if there were significant
differences in response patterns between the two
conditions. It can be seen that participants rated
the frequent email management strategy as
significantly more similar to their usual email
strategy, significantly easier to adopt and
significantly more strictly followed compared to the
once a day email strategy. However, following the
once a day strategy did not lead to significant
reduction in how participants felt about the amount
of time they were spending on email, how
distracted and stressed they were by email, or how
well they felt they were able to mange their inbox.
5. DISCUSSION
The current study investigated the effect of using
two different email strategies on the amount of time
spent on email as well as on subjective self-
How to manage your inbox: is a once a day strategy best?
Bradley ● Brumby ● Cox ● Bird
reported measures, such as stress and level of
distraction caused by email. Firstly, it was found
that the manipulation of email strategy did have an
effect on the participant’s behaviour regarding
email. When using a once a day strategy,
participants checked mail less frequently and spent
less time on email when they were following a
frequent email management strategy. Participants
used fewer but longer sessions in order to handle
their email in the once a day management strategy
as opposed to more regular and shorter sessions in
the frequent email management strategy. This
suggests that participants would spend less time
task switching, therefore avoiding the cost
associated with it identified by previous research
(Perlow, 1999).
It was hypothesised that by using a strategy that
required participants to manage their email inbox
only once a day participants would spend less time
on email than if they used a strategy in which they
frequently managed their email inbox. The results
of this study support this idea and show that
participants spent less time on email when
following the once a day email management
strategy compared to the frequent checking
strategy. These results therefore suggest that a
once a day email management strategy might lead
people to spend less time each day on email.
Another key aspect in assessing the quality of an
email strategy is the ease with which it is adopted.
Participants reported finding it more difficult to
adopt the once a day email management strategy
than the frequent email management strategy. How
easily an email management strategy was adopted
was correlated with how strictly participants
reported following the instructions of the strategy.
This suggests that if a strategy is too difficult to
adopt it is not likely to be followed very strictly. The
ease of adoption of the strategy and how strictly it
was followed were both correlated with how similar
a strategy was to a participant’s usual email
strategy. Therefore, it is suggested that the reason
the once a day email management strategy was
difficult to adopt (and therefore less strictly
followed) is not because of something inherent to
the strategy itself but due to it being more different
to the participant’s usual management strategy.
This was supported by the qualitative data provided
by participants explaining that their usual strategy
was to manage emails as they arrive.
It was also hypothesised that using a once a day
email management strategy could reduce the
amount of stress participants experienced due to
email. The basis of this hypothesis was that
spending less time on email reduces stress (Barley
et al., 2011). The strategy used by participants did
not result in a significant difference in reported
stress levels or the amount of time that participants
spent on email. Although at first this seems like a
negative result there is a positive to be drawn from
it in that participants did not feel more stressed by
adopting the once a day email management
strategy.
5.1 Implications
The finding that participants could spend less time
on email by using a once a day email management
strategy has productivity implications. If an effective
way to implement a once a day email management
strategy could be found that avoids the drawbacks
identified in Mark et al. (2012), such as feelings of
isolation and fear of being overwhelmed by emails,
then employees could spend less time managing
their email inboxes and more time working on other
tasks.
The finding that an email strategy less similar to a
user’s normal email strategy is harder to adopt and
less likely to be followed strictly suggests that in
order to encourage users to adopt a new email
management strategy it would be beneficial to start
with small deviations away from their normal
strategy and gradually move towards larger
changes.
5.2 Limitations
The most critical limitation of the study is the small
sample size. Recruiting participants was difficult
due to the reluctance of users to change their email
management strategy to a once a day strategy.
This reluctance existed as a result of user’s fears
that they would not be able to stay on top of their
email inbox and would become overwhelmed if
they allowed emails to accumulate in their inbox.
This kind of concern is common and has been
expressed by participants of several other studies
(e.g. Barley et al., 2011).
RescueTime could not be installed on iPhones or
iPads and therefore email usage times on them
could not be recorded. This caused a problem
because some participants usually used their
iPhones or iPads as part of their email
management strategy. Ideally only participants who
did not use these devices would be selected for
participation, however due to the previously
mentioned problems with recruiting enough
participants, this was not possible. The best effort
to minimise the effect of this limitation was to
request that participants attempt to avoid using
their iPhone or iPad for email. One way this was
encouraged was suggesting users to turn off push
email in order to reduce the kneejerk reaction of
checking emails on a mobile device as soon as
they arrive. Overall participants reported success in
avoiding using their phones for email.
A further limitation was that all time spent on an
email application was logged under the same title.
This meant that it was not possible to discriminate
How to manage your inbox: is a once a day strategy best?
Bradley ● Brumby ● Cox ● Bird
between the times when participants were using an
email application in order to manage their email
inbox and when they were using it for other things.
For example one participant reported the following:
“Today I used my mail application about three
times when I wasn't specifically checking emails.
Rather I was carrying out a task on my to-do list
that involved the use of my email application: for
example, a colleague sent me some files for a
lecture I was preparing via his public Dropbox
folder, which I opened via mail, and I spent a while
organising the session chairs for a conference I'm
chairing also using email.”
Although on the whole participants were fairly strict
in following each strategy as they were instructed,
multiple participants reported deviating slightly from
the instruction they received, particularly in the
once a day management strategy. This could be
prevented in future studies by offering participants
financial incentives for following the strategies very
strictly.
Future studies could improve on the current study
by testing the measures from the questionnaire in
improved ways. For example, to get an improved
measure of the effect of each email strategy on
stress levels, skin conductance could be used, or
measures of coping and overload as done by
Barley et al. (2011). To measure the effect of email
strategy on how distracted a participant is by email
software that records window changes could be
used or an observer could be present to record the
time taken to resume tasks, similar to the method
used by Mark et al. (2012).
6. CONCLUSION
The results of this study suggest that adopting a
once a day email processing strategy is beneficial
in terms of reducing the amount of time that is
spent on email. This is because email can be more
efficiently worked on in single, longer sessions
rather than by nibbling at it throughout the day.
Surprisingly though this reduction in time spent on
email from following the once a day strategy did not
lead to a reduction in email-related stress, or even
the perception of how much time is being spent on
email. This is likely because most of our
participants were already using an email
management strategy quite similar to a once a day
strategy to manage their email.
7. AKNOWLEDGEMENTS
This work was undertaken as the first author’s BSc
research project at UCL and is part of the Digital
Epiphanies project, supported by the UK
Engineering and Physical Sciences Research
Council [EP/K025392/1].
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