tmailrPrivacy
What a masked email alias actually does
30 July 2026 · 3 min read · TMailr
A masked alias is an address you hand out instead of your own, which forwards to your real mailbox until you decide it should not. That is the whole product. What makes it worth having is not the forwarding, which is trivial, but the switch, which is the part people underestimate.
The problem it solves is not spam
Spam filters are good. The reason to keep your real address out of other people’s databases is not that you will drown, it is that an email address has become an identifier. It is the join key between the shop you bought a kettle from, the forum you posted on once, and the breach dump somebody is scraping next year. Handing the same string to everyone links those together permanently and there is no way to unlink them.
A different address per relationship breaks the join. That is worth something even if not a single one of them ever leaks.
What happens when one leaks
The address you gave one shop starts receiving mail from somebody else. Now you know something specific and provable: that shop sold, lost or shared it. With one address for everything you would know only that you are getting more spam.
And you can act, which is the difference. Switching an alias off stops the mail at the door, and the mail stops for good rather than being filtered forever. Nothing has to change on your side, nothing has to be unsubscribed from, and the sender learns nothing about which mailbox was behind it.
Why this is not plus addressing
you+shop@gmail.com is genuinely useful for filing and for spotting leaks, and it fails at the only part that matters. The tag is one line of code to strip, and anybody building a list strips it. Worse, it contains your real address in the same string, so a leak of the tagged address is a leak of the untagged one. And you cannot switch it off: the mail keeps arriving whatever you do.
Use plus addressing to organise mail you expect. Use aliases for addresses you hand to other people.
What a serious alias has to get right
- Relay the original bytes, so the sender’s DKIM signature survives and the mail is judged on their reputation rather than the relay’s.
- Rewrite the envelope sender, so SPF passes on the way out and bounces come back somewhere useful.
- Confirm the destination before delivering anything, so an alias cannot be pointed at a stranger’s mailbox.
- Say the same thing to a stranger whether the alias is blocked, unconfirmed or does not exist, so probing reveals nothing.
- Notice when the destination stops accepting mail, rather than retrying into a wall for weeks.
What it does not do
An alias hides your address from the sender. It does not hide the message from anyone, does not encrypt anything, and does not make you anonymous: the shop still has your name, your card and your delivery address. It also does not help if you reply from your real mailbox, which puts your real address straight into their thread.
And it is not a disposable address. A disposable inbox is designed to be abandoned; an alias is designed to be kept and controlled. Conflating them is how people end up using a throwaway for their bank.
Where to start
Do not migrate everything. Use an alias for the next thing that asks for your address, and for the two or three existing accounts you would most regret being in a breach dump. The value shows up the first time one of them starts receiving mail it should not, and you can turn it off in a second rather than living with it.
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