May 11 10:13:21 "blabla" sm-mta[9380]: k4B7DLjf009380:
 mx.server.bg [IP-adress] did not issue MAIL/EXPN/VRFY/ETRN
during connection to MTA
 May 11 10:18:21 "blabla" sm-mta[9401]: k4B7ILL9009401:
 mx.server.bg [IP-adress] did not issue MAIL/EXPN/VRFY/ETRN
during connection to MTA
 May 11 10:23:21 "blabla" sm-mta[9406]: k4B7NL14009406:
 mx.server.bg [IP-adress] did not issue MAIL/EXPN/VRFY/ETRN
during connection to MTA

 имам много от тези в маил лога, на какво може да се
дължи???
Как да го оправя ?