Choosing a Domain

The part of an address after the at sign matters more than the part before it. The name is yours to invent and nobody checks it. The domain determines whether the signup form accepts you at all.

Why there is a choice

Domains wear out. A domain used by a public disposable service is eventually noticed, added to the blocklists that signup forms consult, and refused. This is not preventable on a public service: the lists are built precisely by looking at services like this one.

The response is to treat domains as consumables. Several are in circulation at any time, a domain showing signs of being widely blocked stops being offered to new addresses, and fresh ones take its place. Addresses already created on an older domain keep receiving mail, so nothing breaks underneath you.

That is why the list changes over time, and why trying a different domain is the first thing to do when a form refuses your address.

What the options mean

The default. Picked at random from the domains currently in good standing. For most situations this is the right choice and needs no thought.

A specific domain from the list. Useful when one has just been refused. Pick another and try again.

The site's own domain. Available, and it looks tidy, but it is the most recognisable domain we have. It is publicly attached to a service whose purpose is obvious from its name, so it is checked and blocked faster than any other, and it can never be rotated out because the site itself lives there. Choose it when appearance matters more than acceptance.

A private domain. Available with an account. These are never published on any page, never appear in a list a scraper can read, and consequently are absent from the blocklists for far longer. This is the main practical reason to register.

How to choose

Signing up for something ordinary. Take the default. It works most of the time and takes no decisions.

The form just refused you. Switch to another domain from the list. This resolves it more often than not.

A signup that matters and must work first time. Register and use a private domain.

Sharing the address with a person rather than a form. Any of them. A human does not consult a blocklist.

What the name before the at sign changes

Nothing, as far as acceptance goes. Blocklists match on the domain. A clever local part does not help.

It does matter for you, though. A name you chose is far easier to recognise and retype than a random one, which is worth doing when you expect to come back to the address later.

Reserved names are refused: the addresses that receive mail about the domain itself, such as abuse or postmaster. Those must reach us rather than land in somebody's temporary mailbox.

A note on how domains are chosen

The domains offered here do not contain words like temp, trash, fake or disposable. That is deliberate. A domain announcing its own purpose is added to blocklists the moment anybody looks at it, and it also looks worse to the person receiving your address. Ordinary looking domains last longer and attract less attention, which benefits everybody using them.

Why the guest list is short on purpose

Without an account you get one domain: the one this site runs on. That is not a limitation we forgot to lift, it is the mechanism that keeps the other domains working.

Every domain shown to anonymous visitors is scraped within days. There is no way around it: the scraper is an ordinary visitor reading an ordinary page, and no amount of cleverness distinguishes it from a person. A domain that is never displayed publicly has no such exposure, and consequently stays accepted far longer.

So the choice is not between showing you ten domains and showing you one. It is between showing everyone ten domains that burn out in weeks, or keeping them for people who signed in, where they last months.

The site domain is the one we accept losing. It is publicly attached to a service whose purpose is obvious from the name, it will end up on every list, and it cannot be rotated out because the site itself lives there.

What to do when your address is refused

Register, then pick a different domain. That is the whole answer, and it works because the domains behind registration are absent from the lists the form is checking.

If a second domain also fails, the site refuses disposable addresses as a matter of policy rather than by list, and no third attempt will help. At that point use a permanent alias or decide the site does not deserve an address, and the page on being blocked at signup covers the remaining options.

Switching domains without losing the first attempt

Changing domain after a refusal has one trap, and it comes from how guest mailboxes work rather than from the domains themselves.

Asking for a new address as a guest deletes the current mailbox and everything in it immediately. So if the form actually did create the account before it decided to complain, and its confirmation mail turns up thirty seconds later, it arrives at a mailbox that no longer exists. The mail is discarded, nothing bounces, and the account sits there unverified with an address nobody holds.

The order that avoids this: wait a minute and watch the current mailbox first. Plenty of sites accept a signup, then run the domain check asynchronously, so a refusal on screen does not always mean nothing was sent. Only when the mailbox has stayed empty is it safe to take a new address on another domain.

Signed in, the problem disappears. New addresses are added to your ten rather than replacing anything, so the first attempt keeps listening while the second one runs.

What the name field accepts

Three to thirty two characters, lowercase letters and digits, with dots, hyphens and underscores allowed in the middle but not at either end. Capitals you type are converted down, because addresses here are stored and compared in lower case, so the case a form shows you back never matters.

Reserved names are refused, and the list is longer than it looks: not only abuse and postmaster, but every address printed anywhere on this site, such as the one on the contact page. The reason is specific to this service. The site domain is also a mailbox domain, and a guest mailbox opens for whoever knows the address, so an unreserved contact address could be claimed by a stranger who would then read mail intended for us.

Life cycle of a domain here

Understanding this makes the statuses in the interface meaningful.

Active. Offered for new addresses, accepted by most forms.

Burning. No longer offered for new addresses, because refusal rates have climbed. Still receives mail for every address already created on it, so nothing breaks for people who have one.

Retired. Out of circulation entirely.

Addresses never stop working because a domain moved between these states. That is the point of having states at all: a domain can be withdrawn from new use without breaking anything that already exists.