E-mail plug-in antispam software Also called an antispam filter, this program filters emails after they have been downloaded. It is usually designed for personal mail managers, such as Outlook. Server-side antispam software Server-side antispam software scans e-mails for triggers, certain key words and phrases, and aggressive writing styles, and detects them as spam. It is usually offered as an additional service by Internet Service Providers (ISPs). It can cause some legitimate e-mails to be mistaken as spam. Standalone antispam program This antispam software constantly filters incoming e-mails for spam. It usually runs in the background, checking the e-mail server at specific intervals for new emails. It deletes e-mail messages detected as spam from the server itself. | 
