The following provides a list of known gamma codes:
https://apiforums.easylink.com/content/gamma-codes
Since 1001 is not listed, are you able to provide the XDN and MRN for the job. That is the Domain Name and Job Number. We will take a look and see what generated the error code.
What all the possible values available for XDN tag ?
XDN - Xpedite Domain Name.
So XDN tag contains domain which processed that request as value.
Example domain values for Production:
XDDS domains - xsi,sxsi
MR domains- usme,usmr2