If you wanted to send an anonymous email, this guide is for you.

Pre-Requirements
Make sure you already have the email prepared.
When sending the email, use a public wireless network for better anonymity. Do not use a network if they ask for your information. Do not send this from home.
Try to have a machine with a clean OS (no information about you).

Here’s the instructions:

  1. Download Tor browser and install. https://www.torproject.org/download/download.html.en
  2. Open Tor browser.
  3. Go to Hide Me proxy or use another proxy. https://hide.me/en/proxy
  4. From the proxy website, access https://anonymousemail.me/
  5. Now you can type the mail.
  6. Fill “From”, “To”, “Subject”, “Body”. Type a fake From address that will get attention of the recipient.
  7. Click I’m not a robot and select the correct images. If you select the correct images there will be a green tick for the box.
  8. Make sure mail is correct.
  9. Send the mail and you should see a message that tells mail is sent.
  10. close the browser.
  11. Disconnect from the network.
  12. Get out from the place 😀

Here’s a list of anonymous email services, that you can try:
http://www.hongkiat.com/blog/anonymous-email-providers/