Alternatively referred to as a garbage account or trash account, a spam account refers to a secondary account created in e-mail or on a social network. A spam account helps protect a primary account, is a location for an alternate personality, a place to show all posts, or is somewhere to send e-mail that you don't trust.
On social networks
With a social networking account like Facebook or Instagram, a spam account may be created for sharing posts more excessively than on the user's original account. For example, if someone wants to be more selective about the content they share on one account, a "spam account" is often used to put up more frequent, casual posts for closer friends and family members.
As an alternate e-mail address
With e-mail, a spam account is an alternative e-mail address that acts as a "dummy" account to receive automated, impersonal e-mail you may not want to read, such as promotions and newsletters. For example, when signing up for a service, to verify you as a user, it may require e-mail verification. You may not want to use your primary e-mail address to sign up, because the service might send you bulk e-mail that will clutter your inbox. If you have a spam account, you can provide that address for the required verification. The verification e-mail will be sent to your spam account, and any future e-mails from that company can be ignored.
How do you create a spam account?
Most services require no more than a valid e-mail address to sign up for their service. If you create or have access to more than one e-mail address, you could create a spam account using another e-mail address. Services like Twitter offer a user the ability to have multiple accounts and the ease of switching between the accounts you want to use.