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DNS, CNAME & A Records, issues !
My email server is having trouble emailing to anyone who uses 1and1.com as an email host. the error I'm getting is that my DNS is not configured correctly
So I did some research, and from what I gathered - 1and1 won't accept your emails if your RDNS for your email record is a CNAME, they expect your mail record to be an A Record.
Here is my current dns setup:
MX record: mail
CNAME Record: Host: mail, Reference: www
A Record: www IPs: xx.xx.xx.xx, yy.yy.yy.yy
I have lots of questions before I go flipping switches!
1. Does having a CNAME mail record truely pose a problem for 1and1, or am I misreading the problem?
2. Can I have two A records pointing to the same IP like this:
MX record: mail
A Records: Host: Mail, IPs: xx.xx.xx.xx, yy.yy.yy.yy
Host: www, IPs, xx.xx.xx.xx, yy.yy.yy.yy
or do I need to make www a CNAME pointing to mail?
3. If I do need to switch from CNAME to A, what is the BEST way to do this? Do I delete the CNAME after I add the A? Should I have both for a bit while the change propagates?
4. I have a SPF txt record, could this be the problem as well? My Google mail accepts the SPF as good.
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Quote:
1. Does having a CNAME mail record truely pose a problem for 1and1, or am I misreading the problem?
Having a CNAME shouldnt pose a problem, although CNAME's aren't really used as much anymore.
Quote:
2. Can I have two A records pointing to the same IP like this:
MX record: mail
A Records: Host: Mail, IPs: xx.xx.xx.xx, yy.yy.yy.yy
Host: www, IPs, xx.xx.xx.xx, yy.yy.yy.yy
or do I need to make www a CNAME pointing to mail?
You can have as many A records as you like pointing to the same IP address. An A record is an Address record... points a domain / subdomain to an IP address.
Quote:
3. If I do need to switch from CNAME to A, what is the BEST way to do this? Do I delete the CNAME after I add the A? Should I have both for a bit while the change propagates?
Create the A record, delete the CNAME. Although, it really sholdn't matter either way. If this is a dedicated server, or your own server, you'll be required to restart the DNS service.
Quote:
4. I have a SPF txt record, could this be the problem as well? My Google mail accepts the SPF as good.
Probably not an SPF record problem. In the message that is being returned to you, does it mention anything about mail headers... who it's from, etc? If it shows as user@xxx.xxx.xxx.xxx, then your problem is probably an RDNS problem of sorts.
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You don't want your mx record pointing to a cname, so yes, delete the existing mail cname and create a host record for mail. Here's a bit of information why not to use cnames for mx
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Doug G
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Thanks for your posts,
After switching from CNAME to A record, emails no longer got denied!
As a side note, a great way to test SPF I found was to send an email to spf-test@openspf.org - their mail server will deny your mail (on purpose) but the header of the email will contain SPF diagnoses.
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