Zig

GMail SMTP Send using Previously Obtained OAuth2 Access Token

See more GMail SMTP/IMAP/POP Examples

Demonstrates how to send email using GMail and OAuth2 authentication. This example assumes an OAuth2 access token was previously obtained. Zig

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

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

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

    // See Get GMail SMTP Access Token
    // for sample code showing how to obtain a GMail SMTP access token for desktop apps.

    // In this example, our access token was previously saved to the following file which contains JSON like this:
    //     {
    //      "access_token": "ya39.Ci-XA_C5bGgRDC3UaD-h0_NeL-DVIQnI2gHtBBBHkZzrwlARkwX6R3O0PCDEzRlfaQ",
    //      "token_type": "Bearer",
    //      "expires_in": 3600,
    //      "refresh_token": "1/r_2c_7jddspcdfesrrfKqfXtqo08D6Q-gUU0DsdfVMsx0c"
    //     }
    //
    const json = try chilkat.JsonObject.init();
    defer json.deinit();
    json.loadFile("qa_data/tokens/_gmailSmtp.json") catch {
        std.debug.print("Failed to load GMail access token file.\n", .{});
        return;
    };

    const access_token = try json.stringOf(alloc, "access_token");

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

    // Set the properties for the GMail SMTP server:
    mailman.setSmtpHost("smtp.gmail.com");
    mailman.setSmtpPort(587);
    mailman.setStartTLS(true);

    // The SMTP username should be the GMail address of the user's account that authorized your app to send email.
    mailman.setSmtpUsername("chilkat.support@gmail.com");
    mailman.setOAuth2AccessToken(access_token);

    // Create a new email object
    const email = try chilkat.Email.init();
    defer email.deinit();

    email.setSubject("This is a test");
    email.setBody("This is a test");
    email.setFrom("Chilkat <chilkat.support@gmail.com>");
    email.addTo("Chilkat Admin", "admin@chilkatsoft.com") catch {};
    // To add more recipients, call AddTo, AddCC, or AddBcc once per recipient.

    // Call SendEmail to connect to the SMTP server and send.
    // The connection (i.e. session) to the SMTP server remains
    // open so that subsequent SendEmail calls may use the
    // same connection.
    mailman.sendEmail(email) catch {
        std.debug.print("{s}\n", .{try mailman.getLastErrorText(alloc)});
        return;
    };

    // You may close the connection here.  If the connection is kept open,
    // the next call to mailman.SendEmail will continue using the already-established connection
    // (and automatically re-connect if needed).
    mailman.closeSmtpConnection() catch {
        std.debug.print("Connection to SMTP server not closed cleanly.\n", .{});
    };

    std.debug.print("Email Sent via GMail with OAuth2 authentication.\n", .{});
}