TL;DR
Gmail plus addressing lets you append +anything to your Gmail address like [email protected] to create variations that all deliver to the same inbox....
Aspect
Temporary Email Services
Gmail Plus (+) Addressing
Privacy Level
Total anonymity. Your temp email address has no connection to your real identity. Even the temp email service doesn't know who you are. If the address leaks in a data breach, there is nothing for anyone to trace back to you.
Plus addressing provides minimal privacy. Your real Gmail address remains plainly visible. You just strip the "+tag" portion from the end. Any website, spammer or data broker can extract your real address from the plus-addressed version because it is trivially easy. Automated systems regularly strip plus tags to deduplicate email databases.
Setup Required
Open a temp email site and grab an address. It only takes seconds but it operates as a separate service outside your normal workflow. You must keep the temp email tab open if you want to check for incoming messages.
Zero setup is required. You already have this feature if you have a Gmail account. Just type the "+" sign when you sign up for a site. There is nothing to install and no service to visit. The convenience is the main advantage of this method over every other privacy approach.
Cost
Free for basic use. Premium features like longer inbox duration or multiple addresses are available on some services for a small fee.
Completely free. Built into Gmail. No additional cost beyond having a Gmail account, which is also free.
Tracking Leaks
You can't track which service leaked your address because there is no link between the temp address and your real email. If the temp address gets leaked or sold, your real inbox stays completely unaffected. The leak has zero impact on you.
Unique tags like +netflix or +spotify help you identify which service leaked your address. Your real inbox is still exposed though. You can find the source of your spam but you cannot stop it from arriving. This diagnosis is helpful to know but it doesn't solve the problem of spam reaching you.
Website Acceptance
Some websites block known temp email domains. That is a real limitation. Services like NukeMail rotate fresh domains to fix this, but popular temp email domains end up on blocklists quickly.
Some websites strip the "+" and everything after it or reject addresses containing "+". This practice is getting common as websites catch on to the technique. The approach doesn't work everywhere and there's no workaround when a site rejects plus addresses.
Inbox Experience
Nukemail.app gives you a separate inbox on their service. You check for emails there instead of your regular inbox. This can be inconvenient if you're waiting for something important but it also means your primary inbox stays clean.
All emails arrive in your regular Gmail inbox. You can set up filters to auto-label or organize them by the +tag. This way is easier for ongoing use. It does mean promotional and potentially spammy emails land right alongside your important correspondence.
Reply Capability
Cannot reply. Receive-only. Suitable for verification codes and one-time confirmations but not for ongoing conversations.
You can reply to emails through Gmail. The recipient sees the plus-addressed version as your sender address. But since your real address is easy to figure out from the plus address, this method doesn't really protect your privacy during the conversation.
Verdict
Gmail plus addressing isn't a privacy tool. It works for organizing your inbox and tracking which service shared your email, but it doesn't hide your identity. Any website can strip the "+tag" to get your real address. If privacy is your goal, plus addressing alone isn't enough.
Temporary email provides actual anonymity. Your real email address is never involved. Temp email is the right choice for one-time signups, verification codes and services you don't trust with your real inbox. The address exists in complete isolation from your identity.
Plus addressing is useful when you use it with other privacy tools. Using [email protected] makes it easy to set up Gmail filters so you can identify spam sources. Just don't rely on it as your only privacy tool. Pair it with temp email for throwaway use and an alias service for accounts you want to keep.
Plus addressing is just a way to organize your mail and track who sold your data. It doesn't actually provide privacy. If a service strips the +tag and sells your base address to a data broker, plus addressing won't stop them. Temp email keeps your real address out of the picture entirely so that can't happen.
Outlook and Yahoo Mail both support dot-trick and plus-addressing variations but they behave differently. Outlook ignores dots in the local part of the address. Yahoo doesn't support plus addressing at all. This inconsistency across providers makes plus addressing an unreliable technique. You can't count on it working the same way everywhere.