How to undo sent mail?

how to undo gmail?
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some times we may send mails to whom it should not be sent ,such as if a mail for a friend in your company think you
have sent to the boss ?????
because of this funny incidents some may have lost their jobs too
not only in office this may happen even between friends and family

just leave these funny example and consider a case you "if you are a professional and you are sending a mail to your higher official but after sending only you remember that you missed a content in it
at this stage you will definitely loss your professional dignity and you courrage and confidence
so to over come this you should pre enable a precautionary step in gmail (currently gmail offers this) so that you can undo a mail
we will teach you how

as per the image below you go to settings and then click on lap

now you enable the undo send which is rounded on red circle in the below image
here after when ever you send a mail    you will see a pop up  notification as on the printscreen below

but notice that this option will be displayed only for a short while but dont worry you can extend it upto 30 seconds
see the image below and as per it click on setings and then genereal and then on enable undo send change the cancellation period from 10 seconds to 30 seconds

good luck and feel safe

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