I figured this out.
For the benefit of others…..
In AWS - Create your access key, and you are given an Access Key and a Secret Access Key pair.
The Access Key becomes your Username in Mautic.
Then run this simple script in a terminal window:
php -r ' $accessKey = "PASTE_YOUR_SECRET_ACCESS_KEY_HERE"; $message = "SendRawEmail"; $versionInBytes = chr(2); $signatureInBytes = hash_hmac("sha256", $message, $accessKey, true); $signatureAndVer = $versionInBytes . $signatureInBytes; $smtpPassword = base64_encode($signatureAndVer); echo "\n--------------------------------------------------\n"; echo "YOUR NEW SMTP PASSWORD IS:\n" . $smtpPassword . "\n"; echo "--------------------------------------------------\n\n"; '
Replace “Paste Your Secret Access Key Here” with the Secret Access Key from AWS.
This will generate a new key that becomes your password inside of Mautic.
No need to set any options or do anything else extra.
This worked for both 6.0.7 and 6.0.6