The submission server did not advertise the DELIVERBY extension, so a requested delivery deadline (RFC 2852) cannot be honored.
DELIVERBY
This is a local capability failure, not an SMTP reply; it is thrown before the transaction starts.
The submission server did not advertise the
DELIVERBYextension, so a requested delivery deadline (RFC 2852) cannot be honored.This is a local capability failure, not an SMTP reply; it is thrown before the transaction starts.