Feeling overwhelmed by all that email?

Think fast, short and selective: When email piles up, most people send short responses to a small number of incoming messages as quickly as possible.

If you're the one sending the email, you have better odds of getting a response if you send your messages on weekdays, during regular business hours — especially if you can resist the urge to add an attachment.

These are some of the not-so-surprising findings of a large scale study by researchers at Yahoo Labs in Barcelona and the University of Southern California. The researchers analyzed the behavior of more than 2 million users exchanging 16 billion separate emails over several months, which they describe as the largest single study of email behavior to date.

So. Much. Email.

"Email is a ubiquitous communications tool in the workplace and
plays an important role in social interactions," the researchers acknowledge, surprising no one.

They noted that previous studies of email were largely based on surveys and limited to relatively small populations of email users within organizations. This one studied the time it took pairs of users to reply to received messages and the length of the replies sent.

Here are some of the things the study found:

  • Most people write shorter responses to email late in the day and on weekends
  • Younger users generally send faster and shorter replies
  • Men send slightly faster and shorter replies than women
  • Replies from mobile devices were faster and shorter than from desktops
  • Emails without attachments typically got faster replies

The report, Evolution of Conversations in the Age of Email Overload, noted that users naturally compensate for email overload by responding to a smaller fraction of incoming emails and with shorter replies. "However, their responsiveness remained intact and may even be faster," the researchers noted.

They also noted that demographics plays a role. Older users generally replied to a smaller fraction of incoming emails, but their reply time and length were not impacted by overload as much as younger users. Younger users replied faster, but with shorter replies and to a higher fraction of emails.

Researchers defined email overload as not being able to keep up with the volume of incoming email.

Learning Opportunities

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Researchers found that email received during the weekend get significantly shorter replies than those received during the week. And those received at night are far more likely to get short responses, if any at all.

Messages received in the morning get substantially longer replies than those received in the afternoon and evening.

One of the more surprising findings: The younger the user, the quicker the response — a finding many parents will likely challenge. Researchers claim teens respond to email, on average, in 13 minutes. The time climbs with age:

  • 16 minutes for 20 to 35 year olds
  • 24 minutes for 36 to 50 year olds
  • 47 minutes for those 51 and older

In general, people respond faster to email from phones, followed by tablets and desktops. Emails from phones have a median reply time of only 28 minutes, compared to the 57 minutes for the replies from tablets, and 62 minutes for the desktop.

One thing that does stand out here is that adults between 35 and 50 are the most frequent mobile device users with 53 percent using a phone or tablet for email. Teens and young adults are next most likely group to be using them, and more women using mobile devices than men (50 percent to 45 percent).