Xbase++

OAuth2 for a GMail using a P12 Service Account Key

See more GMail REST API Examples

Demonstrates how to use GMail with OAuth2 for a service account within a Google Workspace Account where your email domain is custom (e.g., @yourcompany.com).

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

Xbase++

LOCAL nSuccess
LOCAL oHttp
LOCAL oCert
LOCAL cIss
LOCAL cScope
LOCAL cOauth_sub
LOCAL nNumSec
LOCAL cAccessToken
LOCAL oMailman
LOCAL oEmail

nSuccess := 0

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

oHttp := CreateObject("Chilkat.Http")

//  --------------------------------------------------------------------------------
//  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)
oCert := CreateObject("Chilkat.Cert")
nSuccess := oCert:LoadPfxFile("c:/someDirectory/keys/chilkat25-cbd7b42afbd8.p12", "notasecret")
IF (nSuccess != 1)
    ? oCert:LastErrorText
    oHttp:destroy()
    oCert:destroy()
    RETURN
ENDIF

//  The ISS is your service account email address ending in gserviceaccount.com.
cIss := "chilkatsvc@chilkat25.iam.gserviceaccount.com"

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

//  The sub is your company email address
cOauth_sub := "bob@yourcompany.com"

//  The access token is valid for this number of seconds.
nNumSec := 3600

cAccessToken := oHttp:G_SvcOauthAccessToken(cIss, cScope, cOauth_sub, nNumSec, oCert)
IF (oHttp:LastMethodSuccess != 1)
    ? oHttp:LastErrorText
    oHttp:destroy()
    oCert:destroy()
    RETURN
ELSE
    ? "access token: " + cAccessToken
ENDIF

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

//  -----------------------------------------------------------------------
oMailman := CreateObject("Chilkat.MailMan")

//  Set the properties for the GMail SMTP server:
oMailman:SmtpHost := "smtp.gmail.com"
oMailman:SmtpPort := 587
oMailman:StartTLS := 1

oMailman:SmtpUsername := "bob@yourcompany.com"
oMailman:OAuth2AccessToken := cAccessToken

//  Create a new email object
oEmail := CreateObject("Chilkat.Email")

oEmail:Subject := "This is a test"
oEmail:Body := "This is a test"
oEmail:From := "Bob <bob@yourcompany.com>"
nSuccess := oEmail:AddTo("Recipient", "recipient@example.com")
//  To add more recipients, call AddTo, AddCC, or AddBcc once per recipient.

nSuccess := oMailman:SendEmail(oEmail)
IF (nSuccess != 1)
    ? oMailman:LastErrorText
    oHttp:destroy()
    oCert:destroy()
    oMailman:destroy()
    oEmail:destroy()
    RETURN
ENDIF

nSuccess := oMailman:CloseSmtpConnection()
IF (nSuccess != 1)
    ? "Connection to SMTP server not closed cleanly."
ENDIF

? "Successfully sent email using Gmail with a service account key."

oHttp:destroy()
oCert:destroy()
oMailman:destroy()
oEmail:destroy()