Did you ever handle an email campaign? There is one moment when you have to press the start button to get the campaign going. Mailchimp - a popular mailing application - portrays this by a sweaty, hairy hand that stretches a finger towards a red button but also hesitates and pulls to and fro.
This - I think - appropriately describes the tension behind the simple click on the send button that will release hundreds or thousands of mails. Every mistake still contained in these mails will be multiplied by this number.