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PHP email SDK

The PHP email SDK: receive, read and send mail from PHP.

Receive email in PHP without the IMAP extension or a mail server. Create an address, wait for the next message, read its text, HTML and attachments, and reply in the thread. Mail is stored encrypted and opened by your PHP process with libsodium.

Install the PHP package
composer config repositories.mailcycle composer https://mailcycle.email/php
composer require mailcycle/mailcycle
Create a free accountRead the PHP guide

mailcycle/mailcycle on Mailcycle's Composer repository · PHP 8.1 or later · Apache 2.0 · Free tier, no card

Quickstart

Receive and send email in PHP.

Sign in, create an address, wait for a message and answer it. That is the whole loop, and it is the same loop whether the mail is a sign-up code, a customer or a receipt.

  1. 1Install mailcycle/mailcycle and set MAILCYCLE_PHRASE to your account's recovery phrase.
  2. 2Create an address with $mc->addresses()->create(). It receives mail straight away.
  3. 3Wait for the next message with $mc->messages()->waitFor(), or take it from a webhook.
  4. 4Reply with $mc->messages()->send(), threaded under the original.
The full PHP guide
PHP: create an address, wait for mail, reply
use Mailcycle\Mailcycle;
use Mailcycle\NewAddress;
use Mailcycle\Outgoing;
use Mailcycle\WaitFor;

$mc = Mailcycle::signIn(getenv('MAILCYCLE_PHRASE'));

// A new address that receives mail, sealed to your key.
$address = $mc->addresses()->create(new NewAddress(prefix: 'signup', label: 'Test run 42'));
echo $address->emailAddress, "\n"; // signup-x7k2@...

// Wait for the verification email, decrypted here.
$message = $mc->messages()->waitFor(new WaitFor(addressId: $address->id, subject: 'verification'));
echo $message->subject, ' ', $message->text, "\n";

// Reply in the same thread.
$mc->messages()->send(new Outgoing(
    $address->emailAddress,
    $message->replyTo,
    'Re: Hello',
    'Thanks, confirmed.',
    replyTo: $message,
));
What it does

The whole email API, from PHP.

Everything the Mailcycle console can do is in the package: addresses, inbound mail, sending, webhooks, events, API keys and devices.

Create email addresses from PHP

$mc->addresses()->create() mints a new address on a shared domain, or on your own domain from Scale, and it receives mail at once. Give it a prefix and a label sealed on your machine.

Receive email and wait for it

$mc->messages()->waitFor() listens on the event stream and returns the next matching message, filtered by sender or subject, opened and ready to read. Without a stream it checks every five seconds.

Read and parse incoming email

$mc->messages()->all() and ->attachment() return the sender, subject, plain text, the original HTML, a safe HTML with remote images and trackers removed, and every attachment as bytes.

Send email and reply in the thread

$mc->messages()->send() sends from an address your account owns, with up to ten files. Pass the message you are answering and the threading headers are filled in.

Inbound email webhooks

Register a URL and every message.received event is POSTed to it, signed with HMAC-SHA256 and retried. WebhookSignature::verifyNow() checks the signature in one line.

A live event stream

$mc->events()->stream() carries the same events over a WebSocket the moment they happen, and reconnects after a drop. Events carry ids, never content.

Email testing

Test email verification in PHPUnit, Pest and Laravel Dusk.

Create an address in setUp(), submit it through your registration form with Dusk or a feature test, then call waitFor and read the code from $message->text. A timeout throws an ApiException with the code timeout, so the test fails with a reason.

  • A real address on a real domain, so the mail goes through the same path your users' does.
  • One call blocks until the message lands, filtered by subject or sender, with a timeout you set.
  • Text, HTML and attachments come back parsed, so pulling out a code or a link is a regular expression.
  • Mail received from the moment you start waiting counts, even if it lands before the stream is up.
Inbound email webhooks

Handle incoming email in Laravel, Symfony and Slim.

Rather than polling, let the mail come to you. A webhook POSTs each event to your URL the moment it happens, signed so you can prove it came from Mailcycle, and retried if your server is down.

Events carry ids, never content. Fetch the message by id and it is opened in your code, exactly as it would be otherwise. Webhooks are on Operator and above.

Webhooks in the docs
Laravel routes/api.php: verify, then fetch
use Illuminate\Http\Request;
use Mailcycle\WebhookSignature;

Route::post('/hooks/mailcycle', function (Request $request) use ($mc, $secret) {
    $raw = $request->getContent(); // the body exactly as it arrived
    if (!WebhookSignature::verifyNow($secret, $raw, $request->header('Mailcycle-Signature'))) {
        abort(401);
    }

    $event = json_decode($raw, true);
    if ($event['type'] === 'message.received') {
        $message = $mc->messages()->get($event['payload']['messageId']);
        handle($message->subject, $message->text);
    }
    return response()->noContent();
});
No mail server

Instead of mail(), PHPMailer and imap_open.

PHP's mail() hands messages to a local sendmail, and PHPMailer or Symfony Mailer send through an SMTP server you supply. Reading mail used the IMAP extension, which was unbundled from PHP in 8.4 and now has to be installed from PECL, plus a mailbox and its password.

This package needs neither. An address is one call, mail arrives on a webhook or through waitFor, and each message comes back parsed: sender, subject, text, safeHtml with remote content removed, and attachments as strings of bytes.

It is not a bulk sender. If you need newsletters or high volumes of transactional mail, use a sending service for that; Mailcycle is for addresses your code owns and the mail that comes back to them.

End-to-end encrypted

Mail is opened in your PHP code, not on our servers.

Each address has a key pair derived from your recovery phrase. Incoming mail is sealed to its public key before anything is written down, and the package derives the private key on your machine to open it.

How the encryption works
  • Signing in proves you hold the key by answering a challenge, so the phrase never crosses the wire.
  • Bodies, attachments, address labels and API key names are all sealed. The server stores ciphertext.
  • Mail sealed by one SDK opens in every other, and in the app, because they share one published format.
  • The package is checked against Mailcycle's published test vectors, including the cases that must be refused.
  • Because the server cannot read mail, there is no server-side search. Search runs where the mail is opened.
Use cases

What developers build with the PHP SDK.

It runs in Laravel and Symfony apps, queue workers and cron jobs: anywhere PHP code needs an email address of its own.

End-to-end tests for sign-up and login

Verification emails, one-time passcodes, magic links, password resets and invitations, checked by a real test in PHPUnit, Pest and Laravel Dusk.

A support or orders inbox your code answers

Give an address to a queue, read what customers send, and reply from the address they wrote to, threaded under their message.

Receipts, invoices and alerts as data

Point suppliers, monitoring and other services at an address and pull the text and attachments straight into your own records.

An address per customer, job or device

Mint addresses on demand and keep each stream of mail separate, with its own label, and delete one when the job is done.

Building an AI agent? It can have an inbox too, through the Mailcycle MCP server, without writing any PHP at all.

The package

PHP SDK at a glance.

Maintained by Mailcycle, the team that runs the API.

The Mailcycle PHP SDK at a glance
Packagemailcycle/mailcycle
RegistryMailcycle's Composer repository
Install withComposer
NeedsPHP 8.1 or later
AlsoNeeds the sodium, openssl, curl, json and mbstring extensions, which most builds include. No other dependencies.
LicenceApache 2.0, free to use in your own applications
APIJSON over HTTPS at api.mailcycle.email
GuideThe PHP guide in the docs

What each plan unlocks. Free receives mail. A signed-in session sends from Personal up. API keys and webhooks start at Operator, and sending from an API key at Scale. See pricing.

Questions

PHP email SDK questions.

Add Mailcycle's Composer repository, run composer require mailcycle/mailcycle, sign in with Mailcycle::signIn, and create an address with $mc->addresses()->create(). Mail sent to it is stored encrypted, and $mc->messages()->all() or ->waitFor() returns it decrypted and parsed. No IMAP extension and no mail server.

Call $mc->messages()->send(new Outgoing($from, $to, $subject, $text)) with an address your account owns. Pass replyTo: $message to thread a reply under the original. Sending from a signed-in session works from the Personal plan, and from an API key on Scale and above.

It is served from Mailcycle's own Composer repository at mailcycle.email/php. The first install line adds that repository to your project's composer.json; after that, composer require, update and the lock file work as they do for any other package.

Yes. It is a plain Composer package with no framework dependency, so it works in Laravel, Symfony or plain PHP 8.1 and later. Put the webhook route in routes/api.php so CSRF protection does not reject it.

The package is free and open source under the Apache 2.0 licence. The Mailcycle Free plan costs nothing and needs no card: 3 email addresses and 3,000 messages received a month, receive only. Sending starts on Personal at $7 a month, API keys and webhooks on Operator at $15, and sending from an API key on Scale at $19.

No. Incoming mail is sealed to the address's public key before it is stored, and the private key is derived from your recovery phrase inside your PHP process. The server holds ciphertext it cannot open. Mail you send leaves in plain text so the recipient's server can read it, and the copy kept in Sent is sealed like the rest.

Call $mc->addresses()->create() at the start of the run and delete the address at the end, which frees its place on your plan. Each address receives mail as soon as it exists. This is for testing your own product and for mail meant for you: registering accounts on other services in bulk, or against their terms, breaks the Acceptable Use Policy.

No. Mailcycle is inbound email infrastructure, and sending is there to answer what arrives. Sending is capped at 60 messages an hour per account and 20 an hour per device or agent, with a daily limit set by the plan, and the Acceptable Use Policy rules out bulk, marketing and outreach mail.

The API is plain JSON over HTTPS at api.mailcycle.email, so anything can call it. Message content comes back encrypted, though, and the package is what derives the keys and opens it. Without an SDK you would implement the published encryption format yourself.
Other languages

The same API in every language you use.

Nine SDKs share one encryption format, so a message created by one opens in all the others.

Give your PHP code an email address.

Create an account, create an address, and read what arrives. The free tier needs no card.

Get startedRead the PHP guide