2009-10-15 Discontinuing Wildcard Domains

(Classic Linux only.)

(See updates below.)

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 user@rahul.net. 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 Robert with a login name “robert” may be receiving mail as bob@example.com. His domain is set up as a wildcard domain, so all mail arriving for any user@example.com is accepted. Robert then uses a procmail recipe to discard all unneeded mail. Since all mail for example.com is accepted, mail for bob@example.com is also accepted, and Robert's procmail filter keeps that mail and discards the rest.

(Update. The above example has been updated. When we remove a wildcard domain, we will leave behind a mail forwarding entry with the customer's login name. In the case of Robert above, whose login name is “robert”, we would remove the wildcard entry for arbitrary addresses of the form user@example.com, but leave behind an entry for robert@example.com. Thus mail arriving for robert@example.com will be accepted.)

After all wildcard support is removed, mail arriving for bob@example.com 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 @example.com (THIS IS IRREVERSIBLE).

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.

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

If you don't add all desired email addresses into your custom domain, then some time after October 31, 2009, some or all of your incoming mail will be lost.

Update. If you are adversely affected by this, please log into our new billing system and open a trouble-ticket asking for a delay in the application of this policy to your domain(s), and please mention the domain(s). We will allow wildcard mail acceptance to continue for these domains until November 30, 2009.

Update. Wildcard domains have now been eliminated. Each wildcard domain was replaced by an alias as described above. Please add or readjust aliases as appropriate.

issues/2009-10-15_discontinuing_wildcard_domains.txt · Last modified: 2009-11-12 06:14 by admin
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