Anti-Spam products such as McAfee AntiSpam should block virtually all spam, but you may occasionally still receive messages you don’t want to receive.
If you didn’t opt in to receiving an advertisement, it is unsolicited, and probably spam. if you have given your email address to a reputable company, for example Microsoft or Amazon, they may periodically email you. If you don’t want to receive these adverts any more, these companies respect your privacy and will unsubscribe you from their mailing lists.
Other less reputable companies and spammers sell lists of active email addresses to other 3rd party companies and other spammers, they often use the ‘unsubscribe’ option to verify that an email account is valid, and that the recipient has read and responded to the spam.
Unsubscribing from unwanted mail
To determine whether to Unsubscribe from a mail:
If you are unsure, blacklist the sender using your anti-spam or email application or create an inbox rule to automatically move messages that contain specific phrases to a junk folder. It’s not worth unsubscribing only to end up receiving more spam.
Opt-in Newsletters that you have previously subscribed to can generally be unsubscribed without causing more spam.
If you recognize the sender as someone you have previously bought items from or done business with, the mail is likely to be legitimate.
Look at the header information, the first or second Received: line from the bottom should indicate where the message was originally sent from - if this does not match the urls contained in the message body and the supposed sender of the message, the message is almost certainly spam, do not unsubscribe these mails. The domain names should match all the way through the message, as CAN-SPAM compliant companies are not allowed to hide the origin of the email by law. Spammers often use botnets or remailers to disguise the origin of the mail. If the sending server is obscured or does not match the sender of the message, do not unsubscribe the message.
Look for the unsubscribe link, it will commonly contain a code in the url to identify your email address, this could either be your email address in plan text format e.g. firstname.lastname@example.org or it may contain another identifier e.g. www.domain.com/unsubscribe=8923689368943. If the domain is not familiar to you, the message is likely to be spam.
Below is a quick checklist which may help when deciding whether to unsubscribe or block unwanted mail:
- Is the message from a known sender? If yes, unsubscribe
- Is the message from a reputable company that you have done business with in the past? If yes, unsubscribe
- Is the sender email address of the email always the same? - Blacklist sender
- Does the sender email address change each time but key phrases in the subject/message body stay the same and are safe to block? – Add a content rule to block the messages.