User Tools

Site Tools


2009-10-15 Discontinuing Wildcard Domains

(Classic Linux only.)

This issue affects you only if you have a custom domain in the Classic Linux environment. it does not affect you if your only email address is of the form It also does not affect accounts in the directadmin environment.

Some Classic Linux customers still have wildcard domains in use for accepting mail. A wildcard domain accepts mail for all addresses in the domain. Unfortunately this allows spammers to mount dictionary attacks, which create a heavy machine load. Even though wildcard domains automatically have the heaviest possible spam filtering enabled, this doesn't do much to decrease the load of accepting mail for unknown addresses that will be discarded anyway.

We will be eliminating all acceptance of mail arriving for wildcard domains as of the end of this month, i.e., October 31, 2009.

In some cases, customers receive mail for specific addresses in their domain, but their domain is set up as a wildcard. Such customers may then lose wanted mail unless they take steps to define needed email addresses as described below.

For example, a customer Joe may be receiving mail as His domain is set up as a wildcard domain, so all mail arriving for any is accepted. Joe then uses a procmail recipe to discard all unneeded mail. Since all mail for is accepted, mail for is also accepted, and Joe's procmail filter keeps that mail and discards the rest.

After all wildcard support is removed, mail arriving for will bounce back.

To avoid this problem, please see our page on::

Then add every email address in your domain that you need.

After doing so, use the 'Delete' button to remove your wildcard domain of the form (THIS IS IRREVERSIBLE).

If you don't see any line with just your domain of the form, this means your domains is not a wildcard domain. You can still add/remove email addresses, but there is no need to delete anything.

Once you have done so, only mail for your defined email addresses will be accepted. All other mail will be immediately and efficiently rejected by our servers.

You can also, at the same time, adjust SMTP spam filtering for the email addresses that you add, or switch off all SMTP spam filtering if you wish.

What if you don't add your desired email addresses? After October 31, 2009, all mail arriving for unknown email addresses in your domain will be rejected by our machines, and will bounce back to the sender.

issues/2009-10-15_discontinuing_wildcard_domains.txt · Last modified: 2021/01/30 02:36 by admin