4 postfix warnings

[owl700]

I'm using Release 5.0.2_GA_1975.UBUNTU6 UBUNTU6 FOSS edition

Can i ignore these warnings?

Oct 22 21:41:54 mail postfix/smtpd[22213]: warning: 190.80.149.159: address not listed for hostname tdev149-159.codetel.net.do

Oct 22 21:14:54 mail postfix/smtpd[16412]: warning: 59.165.185.242: hostname 59.165.185.242.man-static.vsnl.net.in verification failed: Name or service not known

Oct 22 19:41:12 mail postfix/smtpd[9604]: warning: 222.252.197.51: address not listed for hostname localhost

Oct 22 18:36:59 mail postfix/smtpd[6276]: warning: valid_hostname: misplaced delimiter: .

[phoenix]

Surely that can't be the first time you've seen that? They're connections that are rejected by the postfix settings and are probably spammers.