Sometimes somebody try to send spam to my mail server mydomain.com, to non-existent mailboxes.
How I can get rid of them?
Log example
"SMTPD" 5616 198271 "2022-05-12 23:58:27.612" "109.201.22.212" "SENT: 220 mydomain.com"
"SMTPD" 5592 198271 "2022-05-12 23:58:27.680" "109.201.22.212" "RECEIVED: EHLO smtp3.mapnaturbine.com"
"SMTPD" 5592 198271 "2022-05-12 23:58:27.681" "109.201.22.212" "SENT: 250-mydomain.com[nl]250-SIZE 307200000[nl]250-AUTH LOGIN[nl]250 HELP"
"SMTPD" 5616 198271 "2022-05-12 23:58:27.753" "109.201.22.212" "RECEIVED: MAIL FROM:<> SIZE=17604"
"SMTPD" 5616 198271 "2022-05-12 23:58:27.754" "109.201.22.212" "SENT: 250 OK"
"SMTPD" 5600 198271 "2022-05-12 23:58:27.832" "109.201.22.212" "RECEIVED: RCPT TO:<nxskcpy@mydomain.com>"
"SMTPD" 5600 198271 "2022-05-12 23:58:27.835" "109.201.22.212" "SENT: 550 Unknown user"
"SMTPD" 5600 198271 "2022-05-12 23:58:27.906" "109.201.22.212" "RECEIVED: QUIT"
"SMTPD" 5600 198271 "2022-05-12 23:58:27.952" "109.201.22.212" "SENT: 221 goodbye"
"SMTPD" 5616 198276 "2022-05-12 23:58:34.670" "195.29.150.139" "SENT: 220 mydomain.com"
"SMTPD" 5620 198276 "2022-05-12 23:58:34.752" "195.29.150.139" "RECEIVED: EHLO mailout2.t-com.hr"
"SMTPD" 5620 198276 "2022-05-12 23:58:34.771" "195.29.150.139" "SENT: 250-mydomain.com[nl]250-SIZE 307200000[nl]250-AUTH LOGIN[nl]250 HELP"
"SMTPD" 5616 198276 "2022-05-12 23:58:34.856" "195.29.150.139" "RECEIVED: MAIL FROM:<>"
"SMTPD" 5616 198276 "2022-05-12 23:58:34.858" "195.29.150.139" "SENT: 250 OK"
"SMTPD" 5592 198276 "2022-05-12 23:58:34.940" "195.29.150.139" "RECEIVED: RCPT TO:<hjsziwgx@mydomain.com>"
"SMTPD" 5592 198276 "2022-05-12 23:58:34.943" "195.29.150.139" "SENT: 550 Unknown user"
"SMTPD" 5620 198276 "2022-05-12 23:58:35.128" "195.29.150.139" "RECEIVED: RSET"
"SMTPD" 5620 198276 "2022-05-12 23:58:35.129" "195.29.150.139" "SENT: 250 OK"
"SMTPD" 5592 198276 "2022-05-12 23:58:35.210" "195.29.150.139" "RECEIVED: QUIT"
"SMTPD" 5592 198276 "2022-05-12 23:58:35.211" "195.29.150.139" "SENT: 221 goodbye"
"SMTPD" 5616 198278 "2022-05-12 23:58:36.029" "87.120.176.62" "SENT: 220 mydomain.com"
"SMTPD" 5620 198278 "2022-05-12 23:58:36.113" "87.120.176.62" "RECEIVED: EHLO web24.netinfo.bg"
"SMTPD" 5620 198278 "2022-05-12 23:58:36.138" "87.120.176.62" "SENT: 250-mydomain.com[nl]250-SIZE 307200000[nl]250-AUTH LOGIN[nl]250 HELP"
"SMTPD" 5600 198278 "2022-05-12 23:58:36.221" "87.120.176.62" "RECEIVED: MAIL FROM:<>"
"SMTPD" 5600 198278 "2022-05-12 23:58:36.223" "87.120.176.62" "SENT: 250 OK"
"SMTPD" 5616 198278 "2022-05-12 23:58:36.308" "87.120.176.62" "RECEIVED: RCPT TO:<wyspsu@mydomain.com>"
"SMTPD" 5616 198278 "2022-05-12 23:58:36.310" "87.120.176.62" "SENT: 550 Unknown user"
"SMTPD" 5620 198278 "2022-05-12 23:58:36.395" "87.120.176.62" "RECEIVED: RSET"
"SMTPD" 5620 198278 "2022-05-12 23:58:36.397" "87.120.176.62" "SENT: 250 OK"
"SMTPD" 5616 198278 "2022-05-12 23:58:36.481" "87.120.176.62" "RECEIVED: QUIT"
"SMTPD" 5616 198278 "2022-05-12 23:58:36.482" "87.120.176.62" "SENT: 221 goodbye"
"SMTPD" 5616 198291 "2022-05-12 23:58:51.628" "37.26.170.60" "SENT: 220 mydomain.com"
"SMTPD" 5592 198291 "2022-05-12 23:58:51.744" "37.26.170.60" "RECEIVED: EHLO freenet.am"
"SMTPD" 5592 198291 "2022-05-12 23:58:51.746" "37.26.170.60" "SENT: 250-mydomain.com[nl]250-SIZE 307200000[nl]250-AUTH LOGIN[nl]250 HELP"
"SMTPD" 5616 198291 "2022-05-12 23:58:51.861" "37.26.170.60" "RECEIVED: MAIL From:<>"
"SMTPD" 5616 198291 "2022-05-12 23:58:51.864" "37.26.170.60" "SENT: 250 OK"
"SMTPD" 5592 198291 "2022-05-12 23:58:51.979" "37.26.170.60" "RECEIVED: RCPT To:<xujoi@mydomain.com>"
"SMTPD" 5592 198291 "2022-05-12 23:58:51.983" "37.26.170.60" "SENT: 550 Unknown user"
"SMTPD" 5620 198291 "2022-05-12 23:58:52.099" "37.26.170.60" "RECEIVED: DATA"
"SMTPD" 5620 198291 "2022-05-12 23:58:52.100" "37.26.170.60" "SENT: 503 Must have sender and recipient first."
"SMTPD" 5616 198291 "2022-05-12 23:58:52.215" "37.26.170.60" "RECEIVED: RSET"
"SMTPD" 5616 198291 "2022-05-12 23:58:52.216" "37.26.170.60" "SENT: 250 OK"
"SMTPD" 5592 198291 "2022-05-12 23:58:52.350" "37.26.170.60" "RECEIVED: QUIT"
"SMTPD" 5592 198291 "2022-05-12 23:58:52.351" "37.26.170.60" "SENT: 221 goodbye"