Every cPanel account has a default mailbox. The main job of the default account is to deal with emails sent to non-existing email addresses. cPanel’s Default Address section lets you define what should happen with such emails.
The default mailbox is created automatically when your cPanel account is set up, and the mailbox can’t be removed. This is because the mailbox does a number of important things.
Throughout this knowledgebase we use the domain example.net to illustrate articles. We got just one proper email account for the domain: email@example.com. Assuming that the DNS is set up correctly emails sent to the email address are delivered to our inbox. But what happens with emails sent to, say, firstname.lastname@example.org? By default, the email is purged and the server fires off a bounce email to the sender. There are other options though, as described below.
The same goes for emails sent from your website. By default, emails sent via for instance PHP scripts are sent from the default mailbox. In our case the emails are sent from email@example.com. If a receiving mail server bounces one of our emails then the bounce email is delivered to the default mailbox (as that is where the email was sent from).
As an aside, your website should really sent emails from a proper mailbox. It’s very convenient that emails can be relayed using the default mailbox, but it is also bad practice. Relying on the default mailbox may cause email delivery issues, and unless you regularly check the default mailbox you won’t see any bounce emails.
The default mailbox also collects system emails. For instance, by default cron job emails are sent to the default account.
There are two common options for dealing with emails sent to non-existing users, as well as a few advanced options. The common options are:
Image: the Default Address interface lets you define how emails sent to non-existing users should be handled.
The default option (discard the email) is sensible. You are likely to find that pretty much all emails sent to non-existing users are spam, so you probably don’t want to forward the emails.
There are a few less common options for dealing with emails sent to the default mailbox. Clicking on the Advanced options link reveals them:
Image: the advanced options.
If you are hosting more than one domain (i.e. if you got one or more addon domains) then you can configure how unrouted mail is handled for individual domains. The default option is to always discard emails sent to non-existing email accounts. However, you can change this default for any individual domain:
In other words, you can choose to discard unrouted emails for example.net but forward unrouted emails for example.com. Again, we recommend you always use the discard option, but if you want you can change the default configuration.