In the world of web hosting, email addresses can either be real or aliases. A real email address is connected to a mailbox on the mail server. That mailbox will hold any messages sent to the address in queue, awaiting the user to either download it or access it from the Web. An alias is an email address that only holds the appearance of a real account. In reality, any messages sent to it will actually be forwarded elsewhere.
Some websites, particularly those owned by organizations or companies, may use a catchall feature on their mail server. Rather than create an email address for several departments, they may create five and have all other inquiries forwarded to a single address. For example, firstname.lastname@example.org, email@example.com, and firstname.lastname@example.org may all be handled by the same department. Rather than have an alias for each, the catchall for that domain could point to billing. This can also be useful for catching typos.
There are drawbacks to catchall email settings. Since any email address that does not have a valid mailbox will be accepted and forwarded to the specified account, your account might receive more spam. Some spam bots will seek out keywords like “admin” and “support” and automatically send spam to accounts on your domain with those prefixes. Individual website owners and small organizations will probably not see the benefits of catching extra spam.
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