Sample code for 30+ languages & platforms
Go

POP3 GMail XOAUTH2 Authentication

See more GMail SMTP/IMAP/POP Examples

Demonstrates using OAuth2 authentication with pop.gmail.com.

Note: This example requires Chilkat v9.5.0.83 or greater.

Chilkat Go Downloads

Go
    success := false

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    mailman := chilkat.NewMailMan()

    mailman.SetMailHost("pop.gmail.com")
    mailman.SetMailPort(995)
    mailman.SetPopSsl(true)

    mailman.SetPopUsername("my_account@gmail.com")

    // If using OAuth2 authentication, leave the password empty.
    mailman.SetPopPassword("")

    // Load our previously obtained OAuth2 access token.
    // See Getting a GMail POP3 OAuth2 Access Token
    jsonToken := chilkat.NewJsonObject()
    success = jsonToken.LoadFile("qa_data/tokens/gmail_pop3.json")
    if success == false {
        fmt.Println(jsonToken.LastErrorText())
        mailman.DisposeMailMan()
        jsonToken.DisposeJsonObject()
        return
    }

    mailman.SetOAuth2AccessToken(jsonToken.StringOf("access_token"))

    // Make the TLS connection to the POP3 server.
    success = mailman.Pop3Connect()
    if success != true {
        fmt.Println(mailman.LastErrorText())
        mailman.DisposeMailMan()
        jsonToken.DisposeJsonObject()
        return
    }

    // Authenticate..
    success = mailman.Pop3Authenticate()
    if success != true {
        fmt.Println(mailman.LastErrorText())
        mailman.DisposeMailMan()
        jsonToken.DisposeJsonObject()
        return
    }

    // Find out how many emails are on the server..
    numEmails := mailman.CheckMail()
    if numEmails < 0 {
        fmt.Println(mailman.LastErrorText())
        mailman.DisposeMailMan()
        jsonToken.DisposeJsonObject()
        return
    }

    // Examine the POP3 session log:
    fmt.Println(mailman.Pop3SessionLog())

    // The POP3 session log will look something like this:

    // **** Connected to pop.gmail.com:995
    // < +OK Gpop ready for requests from 87.9.200.42 l16mb86351205iok
    // > AUTH XOAUTH2 dXNlcj1....VaMDJFAQE=
    // < +OK Welcome.
    // > STAT
    // < +OK 301 1627357
    // 
    // -- Finished.

    // End the POP3 session and close the connection to the GMail server.
    success = mailman.Pop3EndSession()
    if success != true {
        fmt.Println(mailman.LastErrorText())
        mailman.DisposeMailMan()
        jsonToken.DisposeJsonObject()
        return
    }

    fmt.Println("-- Finished.")

    mailman.DisposeMailMan()
    jsonToken.DisposeJsonObject()