I am flooded with these messages. does it mean my server is open for relay? should i be worried?
tcpserver: ok 32516 mail.mydomain.com:192.168.1.2:25 :75.5.19.70::32413 user invalid "null" tcpserver: ok 32518 mail.mydomain.com:192.168.1.2:25 :75.5.19.70::32414 user invalid "null" user invalid "null" tcpserver: ok 32521 mail.mydomain.com:192.168.1.2:25 :75.5.19.70::32415 tcpserver: ok 32522 mail.mydomain.com:192.168.1.2:25 :75.5.19.70::32416 tcpserver: ok 32524 mail.mydomain.com:192.168.1.2:25 :75.5.19.70::32417 user invalid "null" user invalid "null" user invalid "null" tcpserver: ok 32527 mail.mydomain.com:192.168.1.2:25 :75.5.19.70::32418 user invalid "null" user invalid "null" user invalid "null" user invalid "null" user invalid "null" user invalid "null" vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70 vchkpw-smtp: invalid user/domain characters "null":75.5.19.70
