0

I am running Centos 6.4 and have a hostname of web01.domain.com - the system runs PHP, SSH and FTP only with no POP or IMAP mail and just uses Sendmail.

When sending emails via PHP using Sendmail most of them work fine but some are refused due to an invalid sender domain:

May 29 14:13:01 web01 sendmail[3145]: STARTTLS=client, relay=mx01.kundenserver.de.,
version=TLSv1/SSLv3, verify=FAIL, cipher=AES256-SHA, bits=256/256 $150], dsn=4.0.0,
stat=Deferred: 421 invalid sender domain 'web01.domain.com' (misconfigured dns?) 
http://postmaster.1and1.com/error-messages/#invalidsenderdomain

The link above mentions:

An A record or MX record must be assigned to your sender domain in accordance 
with RFC 2181.

My mail is hosted elsewhere so I don't really want to mess around with A records or MX records unless I have to so if I change my hostname to domain.com from web01.domain.com will this fix the issue and what other problems could it cause? If not, what do I need to change at my DNS provider to "fix" this?

Thanks

Improve this question
2
  • 1
    If you downvote please at least have the courtesy to explain why
    – bhttoan
    May 29, 2013 at 16:42
  • A records do not a Mail server make. They just want to have some assurances that the server sending is run by competent admins, and it makes tracing down issues easier also, as servers with bad domains are often enough hijacked. BTW, I didn't downvote you.
    – NickW
    May 29, 2013 at 16:46

1 Answer 1

Reset to default
1

You just need to create an A record for your server, then if you can, set up an RDNS entry. There's no reason to set up an MX record, unless you're expecting it to receive mail.

Improve this answer
7
  • Thank you Nick - I have added an A record for web01 and will wait for it to propogate. Re the Reverse DNS, when I do a "host ip-address" or nslookup what should I see back for this to be correctly configured?
    – bhttoan
    May 29, 2013 at 16:46
  • You would normally do a dig -x <your ip>, it depends on who assigned the IP address to your server, you can normally ask your hosting provider to set up an RDNS entry for your IP (I am assuming it is just for the single server). As for what you should get back, cyberciti.biz/faq/how-to-test-or-check-reverse-dns
    – NickW
    May 29, 2013 at 16:50
  • It is currently pointing to my webhost and not directly to the server so it gives something like ipaddress.mywebhost.com - is that wrong? I will leave it for a few hours until it propogates but want to know if that is what I should expect to see
    – bhttoan
    May 29, 2013 at 16:55
  • It should point to web01.domain.com if at all possible. If not, it shouldn't be the end of the world..
    – NickW
    May 29, 2013 at 16:57
  • Thanks Nick, that's great - will see happens later when DNS has updated
    – bhttoan
    May 29, 2013 at 16:59

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .