Email is one of the most essential things to our life. But do you actually know what happens when you click the “send” button, and how it's sent to your friends?

Hosted by: Hank Green

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Sources:

https://onereach.com/blog/45-texting-statistics-that-prove-businesses-need-to-start-taking-sms-seriously/
http://www.radicati.com/wp/wp-content/uploads/2015/02/Email-Statistics-Report-2015-2019-Executive-Summary.pdf
http://www.wolframalpha.com/input/?i=(205.6+billion)%2F(seconds+in+a+day)
http://www.howtogeek.com/108205/htg-explains-what-can-you-find-in-an-email-header/
https://books.google.com/books?id=50DMBQAAQBAJ&pg=PA273
http://www.samlogic.net/articles/smtp-commands-reference.htm
https://tools.ietf.org/pdf/rfc5321.pdf
http://en.redinskala.com/what-is-the-difference-between-the-heloehlo-commands/
http://www.tldp.org/HOWTO/Spam-Filtering-for-MX/smtpchecks.html
http://www.linuxmagic.com/best_practices/valid_helo_domain.html
http://slett.net/spam-filtering-for-mx/smtpchecks.html
http://whatismyipaddress.com/mail-server
http://computer.howstuffworks.com/dns.htm
http://www.computerhope.com/issues/ch001358.htm
http://computer.howstuffworks.com/e-mail-messaging/email.htm
https://www.spamhaus.org/consumer/definition/
https://expresspigeon.com/blog/2014/07/28/avoid-spam-filters
https://blog.kissmetrics.com/avoid-the-spam-folder/
https://www.ablebits.com/office-addins-blog/2014/01/31/stop-junk-email-outlook/
https://heptagrama.com/spam-detection.htm
https://www.wired.com/2015/07/google-says-ai-catches-99-9-percent-gmail-spam/
https://books.google.com/books/about/Virtual_Unreality.html?id=cePyngEACAAJ
http://whatismyipaddress.com/email-header
http://lifehacker.com/how-spammers-spoof-your-email-address-and-how-to-prote-1579478914
https://books.google.com/books?id=50DMBQAAQBAJ&pg=PA280
https://books.google.com/books?id=50DMBQAAQBAJ&pg=PA286
http://ccm.net/contents/289-messaging-protocols-smtp-pop3-and-imap4
http://whatismyipaddress.com/pop3
http://whatismyipaddress.com/imap
https://www.liquidweb.com/kb/imap-vs-pop3-e-mail/