Что это за ошибка?

Transcript of session follows.

 Out: 220 mx.my-office24.ru ESMTP Postfix (Debian/GNU)
 In:  EHLO fallback4.rambler.ru
 Out: 250-mx.my-site.ru
 Out: 250-PIPELINING
 Out: 250-SIZE 104857600
 Out: 250-ETRN
 Out: 250-STARTTLS
 Out: 250-AUTH PLAIN LOGIN CRAM-MD5
 Out: 250-AUTH=PLAIN LOGIN CRAM-MD5
 Out: 250-ENHANCEDSTATUSCODES
 Out: 250-8BITMIME
 Out: 250 DSN
 In:  MAIL FROM:<> SIZE=3157
 Out: 250 2.1.0 Ok
 In:  RCPT TO:<tresh1@mail1.my-site.ru>
     ORCPT=rfc822;tresh1@mail1.my-site.ru
 Out: 250 2.1.5 Ok
 In:  DATA
 Out: 354 End data with <CR><LF>.<CR><LF>
 Out: 451 4.3.0 Error: queue file write error
 In:  QUIT
 Out: 221 2.0.0 Bye

For other details, see the local mail logfile

Transcript of session follows.

 Out: 220 mx.my-site.ru ESMTP Postfix (Debian/GNU)
 In:  EHLO abusef2.i.mail.ru
 Out: 250-mx.my-site.ru
 Out: 250-PIPELINING
 Out: 250-SIZE 104857600
 Out: 250-ETRN
 Out: 250-STARTTLS
 Out: 250-AUTH PLAIN LOGIN CRAM-MD5
 Out: 250-AUTH=PLAIN LOGIN CRAM-MD5
 Out: 250-ENHANCEDSTATUSCODES
 Out: 250-8BITMIME
 Out: 250 DSN
 In:  STARTTLS
 Out: 220 2.0.0 Ready to start TLS
 In:  EHLO abusef2.i.mail.ru
 Out: 250-mx.my-office24.ru
 Out: 250-PIPELINING
 Out: 250-SIZE 104857600
 Out: 250-ETRN
 Out: 250-AUTH PLAIN LOGIN CRAM-MD5
 Out: 250-AUTH=PLAIN LOGIN CRAM-MD5
 Out: 250-ENHANCEDSTATUSCODES
 Out: 250-8BITMIME
 Out: 250 DSN
 In:  MAIL FROM:<> SIZE=15704
 Out: 250 2.1.0 Ok
 In:  RCPT TO:<fbl@my-site.ru>
 Out: 250 2.1.5 Ok
 In:  DATA
 Out: 354 End data with <CR><LF>.<CR><LF>
 Out: 451 4.3.0 Error: queue file write error
 In:  QUIT
 Out: 221 2.0.0 Bye

For other details, see the local mail logfile