AWS SES send mail with credentials

I'm trying to send email by AWS SES sesMail. But I need to set security credentials while sending email. I read documentation of SES for grails and it states that we need to set it as following,

 mailId = sesMail{
 credentials "New Access Key", "New Secrete Key"
to "email_id"
subject "Subject"
html EmailBodyContent
}

But it doesn't work. Anyone has solution how to do this?