go-simple-mail v2.3.0 Release NotesRelease Date: 2019-12-17 // almost 2 years ago
In this version is possible to specify PLAIN , LOGIN and CRAM-MD5 authentication
For this, in SMTPServer struct obtained by NewSMTPClient() function, the Authentication variable should be a authType: AuthPlain, AuthLogin, AuthCRAMMD5
If was not specified, default is AuthPlain.
Also, added compatibility to Go Modules.