Unicode C

Verify Connectivity to the SMTP Server

Demonstrates the Chilkat MailMan.VerifySmtpConnection method, which tests whether a TCP/IP connection can be established with the configured SMTP server. It verifies connectivity only — it does not authenticate. This example configures the SMTP host and checks whether it can be reached.

Background: When a send fails, it helps to know where it broke. VerifySmtpConnection isolates the first hop — can the client even reach the server on the configured host and port, and complete the TLS handshake? A failure here points at networking, firewall, DNS, port, or certificate issues rather than credentials. Once connectivity is confirmed, VerifySmtpLogin tests the authentication step.

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Unicode C

#include <C_CkMailManW.h>

void ChilkatSample(void)
    {
    HCkMailManW mailman;
    BOOL connected;

    //  Demonstrates the MailMan.VerifySmtpConnection method, which tests whether a TCP/IP
    //  connection can be established with the configured SMTP server.  It verifies connectivity
    //  only (it does not authenticate).

    mailman = CkMailManW_Create();

    //  Configure the SMTP server connection.
    CkMailManW_putSmtpHost(mailman,L"smtp.example.com");
    CkMailManW_putSmtpPort(mailman,465);
    CkMailManW_putSmtpSsl(mailman,TRUE);

    //  Test connectivity to the SMTP server.
    connected = CkMailManW_VerifySmtpConnection(mailman);

    if (connected == TRUE) {
        wprintf(L"Successfully connected to the SMTP server.\n");
    }
    else {
        wprintf(L"Could not connect to the SMTP server.\n");
    }



    CkMailManW_Dispose(mailman);

    }