About CrazyMailing

CrazyMailing is a disposable email service operated by a small independent team. There is no support department and no investor deck. The people who write these pages are the same people who watch the mail queue and decide which domain gets retired next, which is why the guides here read like field notes rather than marketing.

What the service actually does

It accepts mail. That is the entire mechanism, and stating it that plainly rules out most of what people assume.

An address on one of our domains is live the moment it appears on your screen. No confirmation step, no warm-up: the row exists, so the next message addressed to it will be accepted. Then it expires, on a clock short enough that the promise not to read your mail is cheap for us to keep.

Nobody at this end reads it. The design makes that easy rather than virtuous: the contents are deleted on a schedule and were never attached to a name in the first place.

The path a message takes

Worth setting out step by step, because the shape of it explains most of the limits further down this page.

Cloudflare takes delivery. The MX records for our domains point at Cloudflare, not at a mail server of ours. There is no SMTP daemon in this system and no port 25 open anywhere, which removes an entire category of problems that disposable services traditionally have.

A small program parses the MIME. It rejects anything over ten megabytes and does so silently, without a bounce, because a bounce tells a spammer the address was real. Attachments over five megabytes are skipped while the message itself still arrives. Thirty five executable file types are never stored at all: exe, msi, bat, cmd, ps1, vbs, js, jar, apk, dmg, iso, scr, dll and the rest of that family. The filename gets flattened too, since it was written by the sender: line breaks, quotes and slashes become underscores, runs of dots collapse, and anything past a hundred and twenty characters is cut off.

Surviving attachments go to object storage under a key built from the recipient plus a random identifier, so no one can guess the location of somebody else's file. They are always served as downloads, never rendered in the page, and the link you click is signed and valid for five minutes.

The parsed message reaches our server signed. The handoff carries an HMAC signature over the timestamp and the body, and anything older than five minutes is refused, so a captured request cannot be replayed later.

Your open tab is told immediately. The database emits a notification, the web process is already listening, and the message travels down a connection that was open before it arrived. Nothing polls. The previous generation of this service made twenty six thousand polling requests a day per site, each one waking a server to answer "no, still nothing", and that single design choice cost more than everything else combined.

Before any of that is displayed, the HTML is cut down to a whitelist. Scripts, stylesheets, iframes and inline styles are removed with their contents, links are limited to plain web and mail schemes so that no javascript: or data: address survives, and what remains is rendered inside an isolated frame. A message is written by a stranger and shown on our domain, which makes this the single most important piece of code in the service.

Images are the deliberate exception, and it is worth stating plainly. They are fetched from wherever the sender put them, which means a one pixel image can report that the message was opened and roughly when. Blocking them would end that, and it would also turn most legitimate mail into a column of broken icons, which for a receipt or a confirmation is the worse outcome. So the trade stands as it is: opening a message here tells the sender the address is live. The subject line and the sender are visible in the list without fetching anything, and a verification code is often visible there too.

Why the addresses look like real names

The generator produces things like quietriver2841 or mia.reid7395, never temp, trash or a random string of letters. An address that announces its own disposability gets filtered by the recipient before the check on the domain even runs.

The four digits at the end are load bearing. Guest mailboxes open on knowledge of the address alone, which is a deliberate trade, and the trade only holds while the address cannot be guessed. Two digits would leave roughly three hundred and fifty thousand combinations per domain. A script grinds through that much in an afternoon and reads whatever it finds on the way. Four digits push the space past thirty five million, and at that size the exercise stops paying for itself. You can still read the address aloud over a phone, which a random string does not allow.

Nine domains and a burn rate

Nine public domains are in rotation as this is written, and the figure moves.

Each of them wears out along the same path: it gets sampled, it lands on the lists that signup forms consult, and from that point a growing share of websites refuses it. We move it out of circulation and put another one in. Retirement has two stages rather than one, because a domain pulled abruptly would strand people mid-signup. In the first stage it disappears from the front page and keeps delivering to everything issued from it earlier. Only in the second does it stop altogether.

That burn rate is not a defect in the operation, it is the operation. The only honest way to run this is to budget for domains dying rather than to promise that the address you copied today will still be accepted in the spring. Accounts draw from a set we never publish anywhere, which slows the process down without escaping it.

Why this site explains the other side of the signup form

Any number of sites will hand you an address. Very few will tell you what happens to it after you paste it into a form, why the form sometimes rejects it on the spot, and who made that decision.

We are in an unusual position to explain it, because we are the ones being detected. We watch our own domains get sampled, appear on public lists and begin failing at particular forms, and we can measure how long each stage takes. The material on how detection works and how the blocklists get assembled comes out of that, not out of a keyword tool.

The premise underneath the whole site is simple enough. Every registration form is a database, and the address is the field by which that database finds you again, years later, after it has been sold twice.

How it is paid for

Advertising, and nothing else. No paid tier, no trial countdown, no upgrade page, so nothing here is deliberately broken in order to sell you the version that works. We set out the four business models behind free throwaway mail, because knowing which one a service runs on tells you what its operator wants from you.

What we do not collect

There is no IP address column anywhere in the database and no access log behind it. Guest mailboxes are held by a random token in a cookie, not by anything that identifies a person, and that token is not connected to a name, a device or a location. The practical consequence is on the contact page: when someone demands to know who used an address, there is nothing to hand over, and when you report a bug we cannot look up your session either.

The limits we are not going to pretend away

You cannot send mail from here. Not today and not in a later version. A service that lets anonymous strangers send becomes a spam relay within about a week, and the blocking that follows would take the receiving half down with it.

A guest mailbox is not private. The address is the only key to it, and the inbox opens for whoever types the right one. If what arrives would trouble you in a stranger's hands, sign in and use a mailbox tied to an account instead.

Domains fail without warning. A form that took your address last month can refuse it today, with no appeal available, because the refusal is a third party's decision about a list we have no relationship with.

Everything expires, including the things you meant to keep. A guest mailbox lasts a day from your last visit, an account mailbox a week from your last sign in, and no message survives thirty days whatever you do.

It is the wrong tool for anything you must get back into. Banking, tax portals, work, deliveries, domain registration, cloud storage: the address that recovers an account has to outlast the account, and every address here is built to do the reverse. The disclaimer covers that in full.

Bugs, abuse reports and corrections go to the contact page. Corrections in particular are welcome: we would rather fix a wrong sentence than argue with the person who spotted it.