In much the same way that Gmail will disregard dots from email addresses, most email providers will disregard anything in an email address after a plus. To visualize this, email@example.com will go to firstname.lastname@example.org.
This is called plus addressing, and presents a simple and user-friendly option for exercising greater control over how your email address is shared and managed.
When signing up for a service online, e.g. “John Doe’s Meal Deliveries,” provide your email address as email@example.com. If you receive an email from the service that doesn’t include the “+johndoe,” delete it. It could very well contain something you don’t want on your computer.
Additionally, if you start receiving unsolicited mail at firstname.lastname@example.org, you know the service is sharing your email address with other companies and services and can ask them to stop.
If your security software starts flagging emails your email@example.com, it’s possible the service was hacked or their app or website contains malware, in which case you need to immediately change your password, delete any associated apps, and keep an eye out for suspicious activity.
Another benefit of plus addressing is that you can configure your email program or app to filter out incoming messages. If the aforementioned “+johndoe” email address starts to result in a deluge of spam, malware, etc., it’s possible in most modern email clients to create an inbox rule where anything addressed to “+johndoe” gets automatically deleted or moved into a spam folder.
Most major email providers such as Gmail, Outlook, Hotmail, and Protonmail support plus addressing.
A quick way to check to see if it works on your current email account is to simply send yourself an email with “+test” added to it. If it comes through to your inbox intact, you can use it.
The fact that most people don’t use plus addressing means that it’s less likely to be filtered out by hackers and spammers, but it’s still an easy trick to maneuver around.
While plus addressing will be effective to a point, it should be used in concert with updated anti-virus software and proper data hygiene. Continue to monitor all your accounts for suspicious activity, and assume that any email, regardless of how protected you are, has the potential to be a scam.