Rejected

nano testmail.txt
root@dbrt:/etc/mail# clear

root@dbrt:/etc/mail# sendmail -vt < ./testmail.txt
edward.mbene@mail.ru... Connecting to [127.0.0.1] via relay...
220 dbrt.sts.local ESMTP Sendmail 8.15.2/8.15.2/Debian-8; Wed, 4 Jul 2018 09:57:21 +0200; (No UCE/UBE) logging access from: localhost(OK)-localhost [127.0.0.1]
>>> EHLO dbrt.sts.local
250-dbrt.sts.local Hello localhost [127.0.0.1], pleased to meet you
250-ENHANCEDSTATUSCODES
250-PIPELINING
250-EXPN
250-VERB
250-8BITMIME
250-SIZE
250-DSN
250-ETRN
250-AUTH DIGEST-MD5 CRAM-MD5
250-DELIVERBY
250 HELP
>>> VERB
250 2.0.0 Verbose mode
>>> MAIL From:<mark@dbrt.sts.local> SIZE=92 AUTH=mark@dbrt.sts.local
250 2.1.0 <mark@dbrt.sts.local>... Sender ok
>>> RCPT To:<edward.mbene@mail.ru>
>>> DATA
250 2.1.5 <edward.mbene@mail.ru>... Recipient ok
354 Enter mail, end with "." on a line by itself
>>> .
050 <edward.mbene@mail.ru>... Connecting to mail.stscomp.cz. via relay...
050 220 discovery.vshosting.cz ESMTP
050 >>> EHLO dbrt.sts.local
050 250-discovery.vshosting.cz
050 250-PIPELINING
050 250-SIZE 20971520
050 250-ETRN
050 250-STARTTLS
050 250-AUTH DIGEST-MD5 CRAM-MD5 PLAIN LOGIN
050 250-ENHANCEDSTATUSCODES
050 250-8BITMIME
050 250 DSN
050 >>> STARTTLS
050 220 2.0.0 Ready to start TLS
050 >>> EHLO dbrt.sts.local
050 250-discovery.vshosting.cz
050 250-PIPELINING
050 250-SIZE 20971520
050 250-ETRN
050 250-AUTH DIGEST-MD5 CRAM-MD5 PLAIN LOGIN
050 250-ENHANCEDSTATUSCODES
050 250-8BITMIME
050 250 DSN
050 >>> MAIL From:<mark@dbrt.sts.local> SIZE=311 AUTH=<>
050 250 2.1.0 Ok
050 >>> RCPT To:<edward.mbene@mail.ru>
050 >>> DATA
050 554 5.7.1 <edward.mbene@mail.ru>: Relay access denied
050 554 5.5.1 Error: no valid recipients
050 >>> RSET
050 250 2.0.0 Ok
050 <mark@dbrt.sts.local>... Connecting to local...