This error indicates that you have not attempted to authenticate or send login credentials to our servers
Your SMTP Credentials can be found online in the SocketLabs On-Demand Control Panel. Select your server, then go to Configuration > SMTP Credentials > View SMTP Credentials.
After a certain amount of incorrect authentication attempts, our system will block the IP address being used for a few minutes.
When passing SMTP Authentication information to our system, please keep in mind that we currently only support CRAM-MD5 or AUTH authentication types. If you are using our SocketLabs On-Demand Service as a SmartHost for relaying mail from your own server, please see the following article for more information on how to properly configure some common scenarios: How to increase SMTP performance when sending messages through Socketlabs
What if my system is incapable of passing login information along with an SMTP request?
We recommend contacting the vendor of the software you are using for further troubleshooting and assistance.
If the vendor is unable to resolve this, you can allow a static IP address so that all requests from that IP address will pass through into our system and through your account without requiring any credentials.
This method is not recommended, as it creates a potential security issue.
If this is necessary and you have full control over the network traffic for that IP address (such as your own mail server that is being used for SmartHost relaying to us), please open a ticket in our Support Center requesting that we allowlist your IP address. This option is not available to Free Accounts.