On Wed, Mar 18, 2009 at 11:26:14 +1100, Robert S (robert.spam.me.sensel...@gmail.com) wrote:
> I have started getting a lot of these messages over the last few days > in my mail logs. These messages refer to legitimate addresses eg: > > Mar 17 08:59:10 debian sm-mta[29154]: n2GLwjk7029154: > ruleset=check_mail, arg1=<xxxxxxx...@act.gov.au>, > relay=dmz017.dpa.act.gov.au [136.153.14.117], reject=451 4.1.8 Domain > of sender address xxxxx...@act.gov.au does not resolve > Mar 17 09:16:50 debian sm-mta[29224]: n2GMGPd8029224: > ruleset=check_mail, arg1=<xxxxx...@gsahs.health.nsw.gov.au>, > relay=mail.gsahs.health.nsw.gov.au [202.59.31.130], reject=451 4.1.8 > Domain of sender address xxxxx...@gsahs.health.nsw.gov.au does not > resolve > Mar 17 13:57:14 debian sm-mta[30575]: n2H2ullN030575: > ruleset=check_mail, arg1=<n...@tigerairwaysnews.com>, > relay=mail.tigerairwaysnews.com [202.172.235.34], reject=451 4.1.8 > Domain of sender address n...@tigerairwaysnews.com does not resolve > > It appears that at least some of the messages are actually getting > through - there have been no complaints from the staff (maybe they > just don't know whether the messages should have been sent!) and I > sent a test email from one of these domains which got through - > despite an error message in the log with my username from that domain. > > I use a Netgear DG834 router which is set to get DNS settings > automatically from my ISP. I'm running Lenny (recently upgraded from > Etch), Sendmail-8.14.3-5 > > my /etc/resolv.conf > domain XXXXXXX.net.au > nameserver 192.168.0.1 > > 192.168.0.1 is my router address > NB: anything with XXXXXX is fictitious. I am not an expert and use Postfix rather than Sendmail, but as far as I can see this is an MTA configuration issue rather than a DNS problem. Taking your first example: Mar 17 08:59:10 debian sm-mta[29154]: n2GLwjk7029154: ruleset=check_mail, arg1=<xxxxxxx...@act.gov.au>, relay=dmz017.dpa.act.gov.au [136.153.14.117], reject=451 4.1.8 Domain of sender address xxxxx...@act.gov.au does not resolve As it says, the domain of sender address xxxxx...@act.gov.au does not resolve - and it doesn't. There is no A record for act.gov.au (but there is an MX record). Similarly, there is no A record for gsahs.health.nsw.gov.au in your second example. This is more interesting because the host is gsahs.health.nsw.gov.au, but AIUI the domain is nsw.gov.au and that does have an A record. The question is whether you should be rejecting email from any user @act.gov.au just because act.gov.au does not resolve. As I understand it, the important checking should be against the mail host - in the first example this is dmz017.dpa.act.gov.au which correctly resolves to 136.153.14.117. Checking 136.153.14.117 shows that the reverse DNS is also correctly set up. (Your third example may have been a temporary problem as tigerairwaysnews.com does have A and MX records in place). -- Bob Cox. Stoke Gifford, near Bristol, UK. Please reply to the list only. Do NOT send copies directly to me. Debian on the NSLU2: http://bobcox.com/slug/ -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
