What is a “catch-all?
It is a means of receiving any and all email sent to your domain regardless of if the particular account exists or not. For instance, lets say there is an email account called wazzerjbouski@yourdomain.com… people may make a mistake typing in the email address. Making a catch all account will ensure that someone at your domain gets the message. If you were the only user of your domain you could choose to make only one email account in the domain and set it as the catch all. Doing this makes it possible for you to make up email addresses at will. Note that sub accounts are also available meaning that all users have a virtually limitless number of accounts available to them. In general it is not recommended that you create “Catch All” accounts if you have more users in your domain than yourself as a simple typo would result in the catch all account getting the message instead of it being bounced back to the original sender and they then correcting their mistake and re-sending it. Settin
A catch-all is an address that is specified to ‘catch’ any email that is addressed to your domain name, but does not match any of the email addresses set up for that domain name. So if an email is sent to an address that you have not set-up or if the person misspelled the name section of the email address, then the system will catch it and route it to a pre-defined email address. For example: A company has three mailboxes (not aliases) setup for YourDomainName.com.
This is a flag you can turn on for an account that will make all the email sent to email addresses that do not exist for your domain be stored in that account’s mailbox. For example, if the domain foobar.com only has one account, foo with the email address foo@foobar.com, and I make this email address the ‘catch all’, any email sent to info@foobar.com or john@foobar.com or any other email address for the foobar.com domain will be stored in foo’s mailbox instead of bounce back to the sender. Usually email sent to an email address that doesn’t exist will simply bounce and the sender will get a bounce notification. With a ‘catch all’ they will be stored in a mailbox instead of bouncing. This is good if you don’t feel like creating several aliases and map them to your account, but the downside is that you may end up getting more spam.
