Meg Ryan and Tom Hanks' romantic comedy flick, 'You've got mail' set many hearts aflutter, popularizing emails. But this method of communication has many flaws.

Researchers at London's Kingston University said that employees, who have the habit of constantly checking mails, run a higher risk of damaging their mental health and relationship with their colleagues.

Dr Emma Russell, a senior lecturer in occupational psychology, analysed 28 email accounts and identified seven habits that not only increased the workers' stress levels but also caused negative feelings.

Replying to messages immediately was the first deadly 'sin of inbox-ing'. Rapid exchange of messages creates a ping-pong effect where people are pressurised to respond immediately. Not much thought goes into the content of the messages as well.

Also, when a person sends or responds to a mail out of office hours, it gives an impression that the person is an 'eager beaver' but it also suggests that they fail to 'switch off' from their professional life.

The researchers found that some workers are so fond of replying to e-mails, they experience 'phantom alerts' where they feel that their phone just vibrated or bleeped when it actually hasn't. These workers also like to carry their smartphone wherever they go, including to the toilets, just to keep themselves updated with the inbox.

"Back in the dial-up era, when going online had a cost implication, most people checked email maybe once a day and often responded to mails as soon as they read them. Now with broadband and 3G, unlimited numbers of messages can be streamed to you via your smartphone at any time of the day or night. However many of us haven't adapted our behavior to what can seem like a constant stream of mails," Russell said in a press release.

Seven deadly email sins:

1. Ping pong -- constant emails back and forth creating long chains

2. Emailing out of hours

3. Emailing while in company

4. Ignoring emails completely

5. Requesting read receipts

6. Responding immediately to an email alert

7. Automated replies