Persons generating Spam Email (Spammers) will often use a real email address from their list to use in the “From” field of an email. This way the email looks real and is often mistaken by a recipient as a legitimate email with the recipient recognising the email address.
Another reason is that the Spammers real email address is not used and as such cuts down on the hate mail they would likely receive.
“Non-Deliverable” or “Recipient Mailbox is Full”
Using a real email address (Such as yours) a spammer will send out an email message to millions of recipient email addresses. It is then likely that a good percentage of those recipient email addresses will either no longer exist or their mailboxes are full.
Then by default the email engine will send out returned emails to the “Sender” (The email address in the “From” field) providing them with a “Non-Delivery” report or an email advising them that the recipient’s mailbox is full.
While it is extremely annoying when a spammer uses your email address in this way it does not mean that your account has been compromised or that your server or workstation has a virus.
Unfortunately there is nothing that can really be done. Spammers may use your email address to send out millions of spam emails and then move on to use another email address. Once a spammer gets your email address it’s impossible to prevent them from using it in this way.