The following error (Unable to login!The remote server returned an error: (401) Unauthorized.) from DPD is caused when they are not accepting the credentials we are providing them. There are four common causes for this:
Incorrect Username and/or Password - Please make sure the credentials are correct and that there are no hidden spaces. If you need to update your password on the DPD connection, please follow the steps in our DPD Integration help guide.
Incompatible Password - There are some special characters which DPD's API cannot handle within your password such as "!". You may need to update your password on both platforms and try again.
Incorrect Account Type - Please ensure that the correct account type has been set for the credentials you are using IE if you have a DPD local account, you need to set the Type to DPD Local.
If the DPD account has recently been setup and the above is correct, then the account owner will need to contact DPD to enable API access as newly created DPD accounts do not have this enabled by default.