550 error - mail sporatically being sent and recieved by only some servers - HELP!!!
Hi, i'm extremely desperate here and i'd really appreciate all the help you can give me. i appologise - i cannot post proper links because of the 5 post rule before being able to post links. so bare with me.
i'm able to send and recieve mail to some addresses with success. however i can NOT send or recieve to others for some reason (such servers as Cyberus dot ca). Here are my details.
First the error I have recieved on each message sent to Cyberus dot ca from my email server Concept4 dot ca returns this:
From: mailer-daemon (at) concept4 (dot) ca <mailer-daemon at concept4 (dot) ca>Add to Addressbook
To: <user (at) concept4 (dot) ca>
Subject: Mail delivery problems
Date: Wed, 7 Apr 2004 21:54:47 -0400
SMTP error occurred while sending message to following recipient(s)
550 Sender verify failed
my MX is set as so at everydns(dot)net - view attachment for a screenshot of the settings.
You'll notice that i have two A names pointing to my web server and then i have mail(dot)concept4(dot)ca and the MX set to another host on another IP.
Please see the reported readings from dnsreport dot com for concept4(dot)ca:
I'm quite sure that the MX settings are ok but who knows maybe i'm missing something here. I've even checked into abuse (dot) net
it says it can't even connect to the server? weird? yah!
If anyone can solve this for me I'll be in your debt since there's a few users that rely on my service and i haven't found a solution for about a week!
thank you jason! a bite! anyways you're absolutely right on the "verify the existence of email senders" but i'm actually the guy they are trying to verify and i can't seem to understand why one of my email accounts works with sending to them and the other one on the same server is not.
i've put together a couple of the logs for both concept4(dot)ca and eappearance(dot)com. eappearance is working fine and is going through to the exim server at cyberus(dot)ca. concept is not and this has been ongoing although i can't seem to understand why.
could you please have a look on www(dot)eappearance(dot)com. you'll be able to see the exact errors within my mail servers log. that will most likely troulble shoot the problem much better.
It looks like you should be doing a cname record to the mail server instead of an 'a' record. The log indicates that it does not like the 'a' record set for the mail server because it resolves to an IP instead of a name.
Pehaps show the mx record as the main mailserver name on the remote server. Change the cname for mail to also point to the remote mail server.
jason, i was wondering if it wouldn't be too much trouble to show me how that should look. when you say a cname record to the mail server, should i point the cname to the mail servers name - eappearance?
so for example should i enter this into everydns(dot)net?
thanks so much for looking into this for me.
www(dot)concept4(dot)ca A 220.127.116.11
concept4(dot)ca A 18.104.22.168
mail.concept4(dot)ca CNAME eappearance(dot)com
concept4(dot) MX 10 eappearance(dot)com
Last edited by polarunion; 04-08-2004 at 03:03 PM.
THAT WORKED!!!! I can't tell you how long I've been working on this. Literally days if not a week! And for something as small as that.. arghhh. I never really understood CNAME's and have been told in the past that I would never have to use them. anyway I can sleep now. so thanks again. I'm going to create a manual on this for people to see how I did all this to make it work. You'll be able to find it at www.eappearance.com/diy. I'll have written in June sometime so check back if you've come across this before then.
uhg.... someone just informed me that a CNAME record would cause problems for some mail servers and would reject my mail. can anyone help me out any further? it works now, but it's not perfect.. it's a bit messy apparently..
The cname in the example above is just to get a mail client to access the other server when retrieving or sending mail from their mail client. The mx record is what mail server-to-mail server communication uses which is not using a cname. You should not have a problem.
The sending mail servers did not like having an IP as the mail server name. Doing the MX record in the format of host1.com. MX 10 host2.com. is what the mail servers are looking for. It basically tells them what domain the mail needs to be sent to for delivery. If you wanted the mail to go to the same server you are hosting on it would show domain1.com. MX 0 domain1.com. It breaks the conventional internet mail rules if you use a CNAME for the mail exchanger and can possibly cause some servers to not be able to send e-mail to you.
I guess technically you probably could set a 2nd 'A' record for mail.yourdomain.com to the mail server's IP (for mail client access such as Outlook), but I wouldn't set the MX record to mail.yourdomain.com (it will cause problems), set it to the other server's name or the domain that is catching the e-mail on the other server.
FOR CONCEPT: the web server hosting concept and uses eappearance as the mail server
www.concept4.ca A 22.214.171.124
concept4.ca A 126.96.36.199
concept4.ca MX 10 eappearance.com
FOR EAPPEARANCE: the mail server hosting web for eappearance and mail for both eappearance and concept
www.eappearance.com A 188.8.131.52
eappearance.com A 184.108.40.206
eappearance.com MX 10 eappearance.com
i really have to thank you. as you can see i've been trying to find out the most RFC compliant way to do this. it seems there's very little information out there on how to do DNS. If I can ever help you with anything in web creation and design, please let me know! it's more or less my thing.