Most such messages are not single messages, This type of messages are usually formed by appending more than one message to form a big message.
The first part is our ND picked up individual to each of us.
The second part is a standard message...."we mailed you..."
The third part is the time trigger....."It is taking between..."
Mostly probably, in the third part a wrong message code is being triggered OR while making updates to message table, the great software developer or DBA would have updated a wrong message number.
I still wish that this is not an error and our 485's would be approved soon. Good luck to every one of us....