Simple, modern library of services for sending UTF-8 e-mail
Simple services for sending UTF-8 e-mail.
See UPGRADING.md for upgrade instructions.
- SMTP client supports username/password authentication and secure (SSL) sockets.
- Sends MIME-compliant multi-part text/HTML e-mails.
- Handles large attachments using streams for predictable, low memory usage.
- Attachments from memory or from any stream-wrapper.
- Support for inline (image) attachments.
- Multiple recipients for all types of recipient fields.
- Sends multiple e-mails without reconnecting.
Some features are delibarely outside the scope of this project:
Support for arbitrary character sets is omitted - all modern mail clients support UTF-8.
No support for
mail()as a transport method, as this function has constraints that conflict with our objectives - mainly, it does not support streams, which means the entire message has to fit in memory, which leads to unpredictable performance and memory usage.
Mail service implementations are abstracted behind the
MailService interface, which depends
Message model to define the actual content.
To send mail, simply create an instance of
Message, populate it with new instances of
Attachment models by calling various public set/add-methods, then call
The model permits any combination of UTF-8 text and HTML message bodies with any number of attachments.
The following example assumes a
MailService instance named
$service is in scope - subsequent sections
will explain how to configure an e-mail service.
Here's an example of sending a plain-text e-mail with an attachment:
$message = new Message( new Address($email), // recipient new Address("email@example.com"), // sender "Hello, Person!", // subject $text // plain text message body ); $message->addAttachment(Attachment::fromFile(__DIR__ . "/awsum/unicorns.gif")); $service->send($message);
Refer to the
Message model to learn about additional message properties.
SMTPMailService implementation connects directly to an SMTP server via sockets.
To bootstrap an SMTP mail service, you need to select a
Connector, optionally an
implementation - for example:
$service = new SMTPMailService( new SocketConnector("localhost", 25), new LoginAuthenticator("user", "super_secret_pa55w0rd"), "test.org" );
Note the third argument, which is the local host-name - this is used in the handshake (
send to the SMTP server when the client connects.
SMTP protocol-level logging is supported for diagnostic purposes, and can be enabled by injecting
a PSR-3 Logger into
this may be useful if you have connection issues, as it will write a
debug-level entry for every
SMTP command sent, and every response received.
Unlike SMTP protocol-level logging described above, a more general logging facility is also available -
this will write a single log-entry on success or failure to send a message, and is more generally
applicable to any
MailService implementation, including of course the SMTP service.
To write a log-entry to a PSR-3 Logger, use the
implementation, which acts as a decorator for any other
MailService implementation - for example:
$service = new MailServiceLogger($psr_logger, new SMTPMailService(...));
See inline documentation for
MailServiceLogger for details on customizing the message template and log-level.
A passive implementation of
MailService is available, which does nothing.
You can use this during testing/development to disable any outgoing Messages.
This is typically most useful in conjunction with the
MailServiceLogger described above, to bootstrap
a fake mail-service for testing and development, enabling you to see Messages that would have been sent.
To run the integration tests, you will need to set up a local SMTP server for testing.
On Linux, you will likely just have to set up an actual, local SMTP daemon. (see
.travis.yml for an
example of installing and starting
smtp-sink which comes with
You may need to copy
integration.suite.yml to customize the
SMTP host-name, port-number, etc.
This library has a number of stated design objectives:
- Simplicity: UTF-8 is the only supported character-set, we make an effort not to reinvent the wheel (e.g. leveraging base64 and quoted-printable stream-filters) and the library has no external dependencies.
- Using streams for efficiency and predictable memory usage - in particular, file attachments are encoded and sent in chunks, without buffering the entire message or juggling huge strings.
- Separation of concerns - in particular, MIME encoding and SMTP transport concerns ("dot-stuffing") are fully separated, which in turn is made possible by proper use of streams.
- Using dependency injection (primarily constructor injection) everywhere.
- Using abstractions (interfaces) both at the high level and for dependencies/components.