https://kalilinuxtutorials.com/email-spoofing/
https://rutube.ru/video/9b00a49439370640e48de5fa49075724/

https://stackoverflow.com/questions/9763455/how-to-send-a-mail-directly-to-smtp-server-without-authentication

#### Lista de servidores SMTP gratuitos – Servidores SMTP
https://www.e-eeasy.com/free-smtp-server-list-smtp-servers/

https://community.spiceworks.com/t/email-spoofing/785619/2

https://anonymousemail.me/
https://sendity.org/
https://www.proxynova.com/tools/send-anonymous-email/
http://www.sendanonymousemail.net/
https://www.5ymail.com/
https://www.xwebtools.com/send-free-anonymous-email/
http://sendemail.in/sent/