How to Create a Catchall Email Address in ISPConfig

This guide shows you how to create a catchall email address in the ISPConfig control panel on your Noiz hosting account. A catchall (also written catch-all, and sometimes called a wildcard address) collects every message sent to an address at your domain that does not exist as a mailbox, alias or forward, and delivers it into one mailbox you choose. It is a useful safety net for misspelt addresses, but it comes with a real spam trade-off, which this article explains before you switch it on.

Last reviewed: 27 July 2026, against ISPConfig 3.3.1p1. This guide is written for Noiz hosting and is kept current against ISPConfig. It complements, and does not replace, the official ISPConfig documentation linked below.

Official Documentation Reference

• ISPConfig 3 documentation: Catch All Email
• ISPConfig official documentation index

Prerequisites

• You can log in to the ISPConfig control panel.
• A mailbox already exists to receive the caught mail. If not, first create an email mailbox in ISPConfig, for example [email protected].
• Your email domain is already set up on the account and appears in the drop-down lists under the Email tab.

How a Catchall Works

Normally, when someone sends a message to an address that does not exist on your domain, the mail server rejects it and the sender receives a bounce message along the lines of "no such user here". A catchall changes that behaviour: any message addressed to a non-existent address at the domain is delivered to the destination mailbox you nominate instead of bouncing.

• Existing mailboxes, aliases and forwards always take priority. The catchall only receives mail for addresses that are not defined anywhere else on the domain.
• Each domain can have only one catchall address. If you try to add a second, ISPConfig refuses with an error.
• Typical uses: catching mail sent to misspelt addresses such as [email protected], or receiving mail for ad-hoc addresses you hand out without creating each one in advance.

Create the Catchall Address

Step 1: Open the Email Catchall list

1. Log in to the ISPConfig control panel.
2. Click the Email tab in the top navigation bar.
3. In the left-hand menu, under Email Accounts, click Email Catchall. The list of existing catchall entries for your account appears; on most accounts this list is empty.

Step 2: Complete the Email Catchall form

1. Click the Add new Catchall button. The Email Catchall form opens.
2. In the Source drop-down, select the domain the catchall should apply to, for example yourdomain.com. Note the @ sign shown in front of the list: the rule matches every address at that domain that does not otherwise exist.
3. In the Destination Email field, type the full address of the mailbox that should receive the caught mail, for example [email protected]. Use an existing mailbox on your Noiz account, ideally on the same domain, so the mail stays on the server and is easy to manage.
4. Review the optional settings:
   • Send as: cleared by default. When ticked, the destination mailbox is allowed to use addresses in the source domain as its sender address when it authenticates to the mail server over SMTP. Most catchalls do not need this, so leave it clear unless you have a specific reason to change it.
   • Enable greylisting: an anti-spam measure that briefly delays the very first message from an unknown sender. Legitimate mail servers retry automatically, so genuine mail still arrives, just a little later the first time. On a catchall this option is well worth considering, because catchalls attract far more spam than ordinary addresses.
   • Active: ticked by default. The catchall only works while this box is ticked. Unticking it later is a quick way to switch the catchall off without deleting it.
5. Click Save. The new entry appears in the Email Catchall list.

Step 3: Test the catchall

1. Wait a minute or two: ISPConfig applies configuration changes to the mail server on a short cycle, so a brand-new catchall may not take effect instantly.
2. From an outside address, for example a personal webmail account, send a test message to an address on your domain that you know does not exist, such as [email protected].
3. Check the destination mailbox. The test message should arrive there instead of bouncing back to the sender.

The Spam Caveat: Think Before You Rely on a Catchall

Spammers routinely send to guessed and dictionary-generated addresses such as admin@, sales@, john@ and thousands of random variations. Without a catchall, all of that mail is rejected at the door. With a catchall, every one of those guesses becomes a deliverable address, so the destination mailbox can fill with junk quickly. Keep the following in mind:

• Expect more spam. The server-side spam filter still scores incoming mail, but a catchall widens the funnel considerably, and some junk will get through.
• Watch the mailbox quota. A catchall mailbox that nobody empties can hit its storage limit, and once it is full, legitimate mail to that mailbox starts bouncing too. Review and clear it regularly.
• Prefer specific addresses where you can. If you only need a handful of extra addresses, create them individually as aliases or forwards instead of catching everything. That keeps the "no such user" rejection working for everything else.
• Use greylisting. Ticking Enable greylisting on the catchall cuts a large share of low-effort spam at the cost of a short delay on first contact from new senders.
• Switch it off if it becomes a burden. Untick Active on the catchall entry and mail to non-existent addresses will bounce again, while your real mailboxes, aliases and forwards carry on unaffected.

Troubleshooting

• Error "There is already a Catchall record for this domain.": each domain can have only one catchall. Open the existing entry in the Email Catchall list and edit its Destination Email instead of adding a second one.
• Error "Destination is no valid email address.": the Destination Email field needs a complete address including the @ sign and domain, for example [email protected], not just a name like info.
• Error "The max. number of email catchall accounts for your account is reached.": your hosting plan's catchall limit is full. Delete an unused entry, or open a support ticket with the Noiz support team to discuss raising the limit.
• There is no Email Catchall entry in the left-hand menu: the catchall allowance on the hosting plan is set to zero. ISPConfig hides the menu entry completely in that case rather than showing it and refusing on save, so it is easy to mistake for a missing feature. Open a support ticket with the Noiz support team to have the allowance raised.
• The test message bounced instead of being caught: check that the Active box is ticked, allow a couple of minutes after saving before testing again, and confirm you selected the right domain in the Source drop-down.
• The test message arrived somewhere else: the address you tested probably already exists as a mailbox, alias or forward. Those always take priority over the catchall, so pick a clearly random address for testing.
• First messages from new senders arrive late: this is greylisting doing its job; the delay only affects the first message from an unknown sender. If it causes problems, untick Enable greylisting on the catchall entry.
• The destination mailbox is drowning in spam: see the caveat section above. Enable greylisting, empty the mailbox regularly, or deactivate the catchall and create specific aliases for the addresses you actually need.

If you get stuck at any point, open a support ticket with the Noiz support team and include the domain name, the destination email address you entered and, if a test message went missing or bounced, the exact address you sent it to and the complete bounce message text.