From: https://betterbounces.net/

making better email bounces
Understand email bounce messages, how to fix them and get email delivered.
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5.1.1 or 411 or keywords
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Check out common email bounces with the links below.

Encryption Issue Bad Sending Address Message Too LongMailbox FullNetwork Connection 
ProblemSecurity Issue
See more at: https://betterbounces.net/#sthash.mbosTF2P.dpuf

From: http://temp-mail.org/

Forget about spam, advertising mailings, hacking and attacking robots. Keep your 
real mailbox clean and secure. Temp Mail provides temporary, secure, anonymous, 
free, disposable email address.

From: https://www.emailitin.com/

Email It In gives you a personal email address which you can send attachments to. 
Those attachments instantly end up in your GDrive, Egnyte, Dropbox, or OneDrive account.

From: https://haraka.github.io/

Haraka is an open source SMTP server written in Node.js which provides extremely high 
performance coupled with a flexible plugin system allowing Javascript programmers full 
access to change the behaviour of the server. It is used heavily in some high traffic 
sites - see the "Known Users" link above for testimonials

From: http://serversmtp.com/en

turboSMTP is here to help, offering you 6.000 free emails per month (200/day) 
without restrictions and forever. This package is ideal for the ones who want 
to get both a free solution and all the qualities of a dedicated SMTP server. 
No credit cards are required. Try it now!

From: http://mailinator.com/index.jsp

temp email temporary disposable throw away

Free disposable email. Think up and give out a Mailinator address any time you need an email 
address but don't want to get spammed! 

From: http://www.lettermelater.com/forum.php?id=1

LetterMeLater.com allows you to send emails at any future date and time you choose.