What does this error mean (letters are not sent from the server)?

Question

Server equipment

A message that you sent using the -t command line option contained no
addresses that were not also on the command line, and were therefore
suppressed. This left no recipient addresses, and so no delivery could
be attempted.

as a result, letters come from the server to the admin with such an error.
sender addresses are in the same domain zone as the site address.
Tried making sender/receiver different/same - still

Answer 1

All you have to do is translate the message.
The option -tmeans that sendmail will try to take additional recipients from the body of the message. The letter itself, according to manu, must be read from stdin. The error message says that no recipients were found either on the command line (as command parameters) or in the body of the message. Therefore delivery is not possible.