[rt-users] REST/1.0/NoAuth/mail-gateway, Could not load a valid user

[Nadeem Shahbaz]

Hi List,

I really need a solution for it. we are using
http://URL/REST/1.0/NoAuth/mail-gateway to create tickets but it is
returning error, "not
ok - Could not load a valid user" in browser and log having :
[error]: Could not record email: Could not load a valid user
(<prefix>/share/html/REST/1.0/NoAuth/mail-gateway:73)

Kindly solve this problem of mine or point any docs if there is any ?
RT version is 3.6.3

Nadeem