Google has rolled out a new experimental feature for Gmail users, which allows them to pull back an e-mail within five seconds of hitting the send button.

Having just five seconds time to retrieve regrettable e-mails by clicking on "Undo Send" button, Google has now given users of Gmail, what it calls the 'panic button' to retrieve those e-mail messages that contained mistakes or promised files that were never attached.

The 'Undo Send' feature can be activated from the Settings / Labs tab with the button being located next to the "message has been sent" notification and once activated, a new 'Undo' link will come into view next to every sent e-mail confirmation.

By clicking the 'Undo Send ' button within five seconds of sending the e-mail, Gmail will stop the mail from being delivered and take users back to the compose window, where a confirmation of retrieval of the e-mail will be shown.

The 'Undo Send' feature cannot retrieve a message that has already been sent as this new feature only holds an e-mail for just five seconds, which Google engineers think is sufficient time needed for a person wanting to recall an e-mail.

Google is however waiting for reactions from Gmail users worldwide and may enhance the pull back time from 5 seconds to 10 seconds if users feel that the present time is insufficient.

Microsoft Outlook also has the recall feature, but it works only when both the sender and receiver are using a Microsoft's exchange server and only if the message has not been opened by the receiver.

Google has, in the past few months, added several features to Gmail and introduced a new one last month, where Gmail automatically shows the location of an e-mail writer.

The sender's location is determined by the signature feature using public IP and it has a disable option to those who do not want to disclose their location.

In January, Google bought out an updated version of Gmail, where users could access their accounts without an internet connection.

This updated version was bought out to give users the benefit of using this service on a flight, where users can read e-mail, compose new ones and archive, while still in the air without an Internet connection.