Drop connections with no MX record

[drsceifers]

Here is what we need to do.

We have wildcard DNS entries for domains like XX.com that we answer web requests to. So, computer.XX.com would put up a page with information related to computers.

Recently we saw Exim trying to accept emails for sites hosted on cPanel. One example was mary.little@yahoo.XX.com which is clearly not a valid email address. We came to the conclusion that Exim was looking up an A Record if no MX Record existed. (expected in RFC)

What we would like to do is to drop connections for Recipients whose domains do not have an MX record. In other words, we just want to drop people trying to deliver to mary.little@yahoo.com.com because we would never want to see those emails. They are certainly trash to us.

We own the server & control all of the domains on it. We have some wildcard DNS entries (A Record) that we serve up related search pages on. The problem is there is no MX record for the wildcarded domains.

In fact, we are trying to break delivery to sites with an A, but no MX record. We are trying to drop the 100-150000 emails that go nowhere every day. Exim is crushing that box because of this traffic. T

An exim user suggested we use "mx_domains = *" but they did not tell us where it would go in the configuration.

In addition, because this is a cpanel box, we need to use cpanel to make this update. Has anyone used a similar ACL and can you tell me the best way to enter it?

Thanks

Don

[drsceifers]

Are there no Exim experts in the group?

[sparek-3]

You might try the exim mailing list:

http://www.exim.org/maillist.html

You might want to search the archives first and see if this question has already been answered.

You might also try removing the domain names from the /etc/localdomains file. Exim will not accept messages for domain names that are not listed in /etc/localdomains or /etc/secondarymx. Though I am not sure how cPanel's implementation of wildcard domain names works and what entries are in /etc/localdomains in this situation.

[drsceifers]

Thanks

I had tried the exim mailing list, but the mxdomains=* I listed was all they had to offer.

I also tried to search first, but could not find any terms to limit the volume that would give a useful result.

As for the wildcards, they are unfortunately not in the /etc/localdomains file.

The exim group suggested the mxdomains=* for the ACL, but I don't know where to place that on a cpanel system.