(Perl) OAuth2 for a GMail using a P12 Service Account Key

See more GMail REST API Examples

Note: This example does not work for Personal Google Accounts where the email domain is @gmail.com

For more information, see https://www.chilkatsoft.com/google_workspace_setup_smtp_gmail.asp

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux

use chilkat();

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

$http = chilkat::CkHttp->new();

# --------------------------------------------------------------------------------
# For a step-by-step guide for setting up your Google Workspace service account,
# see Setup Google Workspace Account for Sending SMTP GMail from a Service Account
# --------------------------------------------------------------------------------
# Begin by loading your Google service account key (.p12)
$cert = chilkat::CkCert->new();
$success = $cert->LoadPfxFile("c:/someDirectory/keys/chilkat25-cbd7b42afbd8.p12","notasecret");
if ($success != 1) {
    print $cert->lastErrorText() . "\r\n";
    exit;
}

# The ISS is your service account email address ending in gserviceaccount.com.
$iss = 'chilkatsvc@chilkat25.iam.gserviceaccount.com';

# The scope is always the following string:
$scope = "https://mail.google.com/";

# The sub is your company email address
$oauth_sub = 'bob@yourcompany.com';

# The access token is valid for this number of seconds.
$numSec = 3600;

$accessToken = $http->g_SvcOauthAccessToken($iss,$scope,$oauth_sub,$numSec,$cert);
if ($http->get_LastMethodSuccess() != 1) {
    print $http->lastErrorText() . "\r\n";
    exit;
}
else {
    print "access token: " . $accessToken . "\r\n";
}

# The access token allows us to send unlimited emails while it's valid. Once it expires, we must obtain and use a new one.

# -----------------------------------------------------------------------
$mailman = chilkat::CkMailMan->new();

# Set the properties for the GMail SMTP server:
$mailman->put_SmtpHost("smtp.gmail.com");
$mailman->put_SmtpPort(587);
$mailman->put_StartTLS(1);

$mailman->put_SmtpUsername('bob@yourcompany.com');
$mailman->put_OAuth2AccessToken($accessToken);

# Create a new email object
$email = chilkat::CkEmail->new();

$email->put_Subject("This is a test");
$email->put_Body("This is a test");
$email->put_From('Bob <bob@yourcompany.com>');
$success = $email->AddTo("Recipient",'recipient@example.com');
# To add more recipients, call AddTo, AddCC, or AddBcc once per recipient.

$success = $mailman->SendEmail($email);
if ($success != 1) {
    print $mailman->lastErrorText() . "\r\n";
    exit;
}

$success = $mailman->CloseSmtpConnection();
if ($success != 1) {
    print "Connection to SMTP server not closed cleanly." . "\r\n";
}

print "Successfully sent email using Gmail with a service account key." . "\r\n";