(Lianja) 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

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

loHttp = createobject("CkHttp")

// --------------------------------------------------------------------------------
// 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)
loCert = createobject("CkCert")
llSuccess = loCert.LoadPfxFile("c:/someDirectory/keys/chilkat25-cbd7b42afbd8.p12","notasecret")
if (llSuccess <> .T.) then
    ? loCert.LastErrorText
    release loHttp
    release loCert
    return
endif

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

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

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

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

lcAccessToken = loHttp.G_SvcOauthAccessToken(lcIss,lcScope,lcOauth_sub,lnNumSec,loCert)
if (loHttp.LastMethodSuccess <> .T.) then
    ? loHttp.LastErrorText
    release loHttp
    release loCert
    return
else
    ? "access token: " + lcAccessToken
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.

// -----------------------------------------------------------------------
loMailman = createobject("CkMailMan")

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

loMailman.SmtpUsername = "bob@yourcompany.com"
loMailman.OAuth2AccessToken = lcAccessToken

// Create a new email object
loEmail = createobject("CkEmail")

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

llSuccess = loMailman.SendEmail(loEmail)
if (llSuccess <> .T.) then
    ? loMailman.LastErrorText
    release loHttp
    release loCert
    release loMailman
    release loEmail
    return
endif

llSuccess = loMailman.CloseSmtpConnection()
if (llSuccess <> .T.) then
    ? "Connection to SMTP server not closed cleanly."
endif

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


release loHttp
release loCert
release loMailman
release loEmail