Guides

Everything you can do with a mailbox that costs nothing and disappears on its own — signing up without your real address, reading mail from a test suite, and turning a domain you own into a catch-all inbox.

  • 46 guides
  • 10 topics
  • Updated 15 September 2026
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Latest guides

A blue envelope floating beside a grey stopwatch with a blue circular arrow looping around it API & automation Waiting for an email in code: polling without a webhook What push and pull each cost you and why a receive-only service has neither webhook nor callback, the four-line loop everybody writes first and the five things wrong with it, why a deadline is the only stopping condition that survives a slow queue, how to choose an interval when the floor is one request a second, reading Retry-After instead of guessing, the whole table of refusals so a 404 is never mistaken for an empty mailbox, deciding which message is yours before you open it, acting exactly once when a poll is retried, and the server-side wait an agent can use instead of a loop. 29 min readIntermediate
  1. A blue envelope floating beside a grey clipboard marked with a large blue tick, with a smaller grey card marked with a cross tilted in front of them Email & deliverability Email address validation: what a regex can and cannot prove The four questions hiding inside « is this a valid email address », why there is no official regex and which one to use instead, the six legal addresses forms wrongly throw out, the three length limits worth hard-coding, the one DNS lookup that catches the commonest real mistake, why an SMTP probe answers yes to addresses that do not exist, the honest case for and against blocking disposable domains, and the confirmation loop that is the only check that proves anything. 21 min read
  2. A blue envelope turned back in mid-air beside the slot of a grey letterbox, with a second blue envelope fallen below it Email & deliverability Email bounces: how to read one, and what each code means What a bounce actually is and the two very different moments it happens, the three parts of a delivery report and which line carries the reason, how to read a reply code and an enhanced status code, the dozen codes that account for almost every bounce anybody reads, what can and cannot bounce at a disposable address, the bounces that belong to the hour you point your own domain here, and why a report sometimes arrives for a message you never sent. 22 min read
  3. A blue envelope floating beside a grey signpost with two blank arm-boards pointing in different directions Email & deliverability MX records explained: priority, lookups and what breaks What an MX record is and the four things it is not, reading one with dig, nslookup or host, what the preference number actually decides and why a backup host is not a second chance, the seven steps a sending server takes, what happens when there is no MX at all and what a null MX says instead, the six ways the record breaks, the single record that points a domain here, and why an hour is not long enough. 18 min read

Start here

4 guides, in the order they make sense — about 52 minutes end to end.

  1. A blue envelope with a perforated edge and a torn-off corner drifting away as small squares, on a grey pedestal beside a small grey bin What is temp mail? Temporary email addresses, explained 12 min readBeginner
  2. A blue envelope standing behind a frosted glass panel with a keyhole in it Sign up for anything without giving your real address 9 min readBeginner
  3. Envelopes travelling along a track through three arch gates, with a stopwatch beside it Test an email verification flow end to end 22 min readIntermediate
  4. A white globe with a blue route arcing over network cubes into a mailbox Turn a domain you own into a catch-all inbox 9 min readIntermediate

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