This is a paid asset, but now you can download EzSMTPMailer Free.
Detail this asset from Unity Store: Original Link
EzSMTPMailer v1.1 (Latest version)
“If possible, please buy the package to support the developer”
– This Asset is easy to implement the ability to send mail by using the Simple Mail Transfer Protocol (SMTP).
– Mail is sent asynchronously.
– You can cancel the transmission while transmitting.
– You can set the event method when the mail send operation is complete.
– You can set the encoding fromDisplayName, subject, body.
– To get the play of the game parameters for debugging purposes.
– In order to get the Exception Logs.
– To receive the data, instead of if you can not provide a server.
Operation check Environment:
– iPhone5 (iOS6.1.3)
– Android4.0 (SH-02E)
– UnityEditor (Windows, Mac)
– Doesn’t work on Webplayer.
– Tested the SMTP feature at Yahoo! mail and Gmail. (In Japan)