Here's some good news: It's possible to unsend an email in Gmail. So, whether you misspelled a word, forgot to attach a document, or called someone by the wrong name, there's an easy way to fix the problem. You'll just have to be quick about it.
How to unsend an email in Gmail
To recall an email, you'll need to use Gmail's Undo Send tool. After you send an email, you'll see a Message Sent box in the lower left corner of your screen. You'll have he option to Undo or View Message. Click Undo.
If you don't change your settings, you'll have about 5 seconds to unsend the message. To give yourself more time (highly recommended), go to Settings in the top right corner. Tap See All Settings. Next to Undo Send, select a Send cancellation period of 5, 10, 20, or 30 seconds. If you realize you need to unsend an email after 30 seconds, you're out of luck.