Directories are another source of e-mail addresses. The more Internet activity you participate in, the more likely you'll end up in a spam list. Delete the message. Think of it in the same context as throwing away the junk mail you receive at home. This can inadvertently cause all original addressees to receive the reply, causing another flood.
Mailing lists can explode into thousands of recipients.
It may also result in hardening your address onto spam lists, as it serves as a confirmation that your account is active and the mail is being read. For advertising purposes, this makes your address more valuable. Set up mail filtering rules to automatically delete the mail, or move it to a separate mail folder. Filtering the mail is particularly helpful if you are unlucky enough to receive offensive spam. In most instances, if you do not respond to the mail, it will stop in days, weeks, or up to a few months.