Swift

SMTP Inspection

See more SMTP Examples

Examine an SMTP session to view all communications sent to the SMTP server. Swift

func chilkatTest() {
    var success: Bool = false

    let mailman = CkoMailMan()!

    mailman.smtpHost = "smtp.example.com"
    mailman.smtpUsername = "myUsername"
    mailman.smtpPassword = "myPassword"

    mailman.smtpPort = 465
    mailman.startTLS = true

    let email = CkoEmail()!

    email.subject = "This is a test"
    email.body = "This is a test"
    email.from = "Alex <alex@example.com>"
    email.add(to: "Christoph", emailAddress: "christoph@example2.com")
    email.addBcc(friendlyName: "Victor", emailAddress: "victor@example3.com")

    // Generate the MIME that is sent when SendEmail is called
    var mimeStr: String? = mailman.render(toMime: email)
    print("\(mimeStr!)")

    success = mailman.sendEmail(email: email)
    if success == false {
        print("\(mailman.lastErrorText!)")
        return
    }

    success = mailman.closeSmtpConnection()
    if success != true {
        print("Connection to SMTP server not closed cleanly.")
    }

    // Examine the SMTP session log.
    print("----")
    print("Smtp Session Log:")
    print("\(mailman.smtpSessionLog!)")

    // ---------------------------------------------------
    // Sample output:
    // ---------------------------------------------------

    // MIME-Version: 1.0
    // Date: Fri, 06 Mar 2026 16:21:00 -0600
    // Message-ID: <A5DC25990C93EC2676F4FBB2BB3BFA9EB34FF9D3@CHILKAT25>
    // Content-Type: text/plain; charset=us-ascii; format=flowed
    // Content-Transfer-Encoding: 7bit
    // X-Priority: 3 (Normal)
    // Subject: This is a test
    // From: Alex <alex@example.com>
    // To: Christoph <christoph@example2.com>
    // Bcc: Victor <victor@example3.com>
    // 
    // This is a test
    // ----
    // Smtp Session Log:
    // 220 smtp.example.com ESMTP Amazon WorkMail SMTP Service
    // EHLO MYCOMPUTER<CRLF>
    // 250-smtp.example.com
    // 250-8BITMIME
    // 250-AUTH PLAIN LOGIN
    // 250 Ok
    // AUTH LOGIN<CRLF>
    // 334 VXNlcm5hbWU6
    // YWRtaW5AY2hpbGthdHNvZnQuY29t<CRLF>
    // 334 UGFzc3dvcmQ6
    // {PasswordOrCredentials}
    // 235 Authentication successful.
    // MAIL FROM:<alex@example.com><CRLF>
    // 250 Ok
    // RCPT TO:<christoph@example2.com><CRLF>
    // 250 Ok
    // RCPT TO:<victor@example3.com><CRLF>
    // 250 Ok
    // DATA<CRLF>
    // 354 End data with <CR><LF>.<CR><LF>
    // {388 bytes} <--- The MIME source of the email (examined via RenderToMime) was sent here.
    // <CRLF>.<CRLF>
    // 250 Ok
    // QUIT<CRLF>
    // 221 Bye

}