False Positives, Whitelists, Blacklists, Spam, Ham, Quarantine Mailboxes, tarpitting, etc. The terminology of email filtering can get a bit confusing. So I’m going to have a go at explaining the most common questions I am asked.
Q: Why do I get spam, I didn’t before? Spammers get your email address from websites (don’t ever put your address on your website in plain text), when you register at other sites (it’s best to have a specific “register@” email address so you can register without using your personal email address), and from other spammer address lists (once you’re on one list it’s only a matter of time before it spreads to multiple lists).
Q: I have a spam filter, why do I still get spam? The spam filter is a program, some are better than others, which scores each email which passes through. The scores are based on the sender’s email address, the senders email domain, the content of the email, the server it came from, etc. If the email reaches a certain score the spam filter will mark it as SPAM..
Q: What is a Quarantine Mailbox? When an email is marked as spam, the filter will send the email to a quarantine mailbox. The vast majority of quarantined email is spam, but occasionally a good email (ham) will end up in the quarantine mailbox- therefore it’s a good idea to check it once per day.
Q: The same person sends me an email, sometimes it’s marked as spam, sometimes not, why? The sensitivity of your spam filter is probably high and that person may have some issues which are affecting their score. Each email is scored individually- so it’s possible for the same person to pass through and then be rejected by the spam filter. I would Whitelist that person.
Q: What is a whitelist? You can whitelist an email address or an entire domain (e.g. @datatroop.com) so they are never caught in the spam filter again. It is the opposite of blacklisting an email address or domain.