Zig

SMTP Inspection

See more SMTP Examples

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

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

    const mailman = try chilkat.MailMan.init();
    defer mailman.deinit();

    mailman.setSmtpHost("smtp.example.com");
    mailman.setSmtpUsername("myUsername");
    mailman.setSmtpPassword("myPassword");

    mailman.setSmtpPort(465);
    mailman.setStartTLS(true);

    const email = try chilkat.Email.init();
    defer email.deinit();

    email.setSubject("This is a test");
    email.setBody("This is a test");
    email.setFrom("Alex <alex@example.com>");
    email.addTo("Christoph", "christoph@example2.com") catch {};
    email.addBcc("Victor", "victor@example3.com") catch {};

    // Generate the MIME that is sent when SendEmail is called
    const mime_str = try mailman.renderToMime(alloc, email);
    std.debug.print("{s}\n", .{mime_str});

    mailman.sendEmail(email) catch {
        std.debug.print("{s}\n", .{try mailman.getLastErrorText(alloc)});
        return;
    };

    mailman.closeSmtpConnection() catch {
        std.debug.print("Connection to SMTP server not closed cleanly.\n", .{});
    };

    // Examine the SMTP session log.
    std.debug.print("----\n", .{});
    std.debug.print("Smtp Session Log:\n", .{});
    std.debug.print("{s}\n", .{try mailman.getSmtpSessionLog(alloc)});

    // ---------------------------------------------------
    // 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
}