Many PHP developers utilize email in their code. The only PHP function that supports this is the `mail()` function. However, it does not provide any assistance for making use of popular features such as HTML-based emails and attachments.
Formatting email correctly is surprisingly difficult. There are myriad overlapping RFCs, requiring tight adherence to horribly complicated formatting and encoding rules - the vast majority of code that you'll find online that uses the `mail()` function directly is just plain wrong!
*Please* don't be tempted to do it yourself - if you don't use PHPMailer, there are many other excellent libraries that you should look at before rolling your own - try SwiftMailer, Zend_Mail, eZcomponents etc.
The PHP `mail()` function usually sends via a local mail server, typically fronted by a `sendmail` binary on Linux, BSD and OS X platforms, however, Windows usually doesn't include a local mail server; PHPMailer's integrated SMTP implementation allows email sending on Windows platforms without a local mail server.
PHPMailer is available on [Packagist](https://packagist.org/packages/phpmailer/phpmailer) (using semantic versioning), and installation via composer is the recommended way to install PHPMailer. Just add this line to your `composer.json` file:
If you want to use the Gmail XOAUTH2 authentication class, you will also need to add a dependency on the `league/oauth2-client` package in your `composer.json`.
Alternatively, if you're not using composer, copy the contents of the PHPMailer folder into one of the `include_path` directories specified in your PHP configuration and load each one manually.
While installing the entire package manually or with composer is simple, convenient and reliable, you may want to include only vital files in your project. At the very least you will need [src/PHPMailer.php](https://github.com/PHPMailer/PHPMailer/tree/master/src/PHPMailer.php). If you're using SMTP, you'll need [src/SMTP.php](https://github.com/PHPMailer/PHPMailer/tree/master/src/SMTP.php), and if you're using POP-before SMTP, you'll need [src/POP3.php](https://github.com/PHPMailer/PHPMailer/tree/master/src/POP3.php). You can skip the [language](https://github.com/PHPMailer/PHPMailer/tree/master/language/) folder if you're not showing errors to users and can make do with English-only errors. If you're using Google XOAUTH2 you will need `src/PHPMailerOAuth.php` and `src/OAuthProvider/Google.php` classes, as well as the composer dependencies. Really, it's much easier to use composer!
While installing the entire package manually or with composer is simple, convenient and reliable, you may want to include only vital files in your project. At the very least you will need [src/PHPMailer.php](https://github.com/PHPMailer/PHPMailer/tree/master/src/PHPMailer.php). If you're using SMTP, you'll need [src/SMTP.php](https://github.com/PHPMailer/PHPMailer/tree/master/src/SMTP.php), and if you're using POP-before SMTP, you'll need [src/POP3.php](https://github.com/PHPMailer/PHPMailer/tree/master/src/POP3.php). You can skip the [language](https://github.com/PHPMailer/PHPMailer/tree/master/language/) folder if you're not showing errors to users and can make do with English-only errors. If you're using Google XOAUTH2 you will need [src/PHPMailerOAuth.php](https://github.com/PHPMailer/PHPMailer/tree/master/src/PHPMailerOAuth.php) and [src/OAuthProvider/Google.php](https://github.com/PHPMailer/PHPMailer/tree/master/src/OAuthProvider/Google.php) classes, as well as the composer dependencies. Really, it's much easier to use composer!
PHPMailer defaults to English, but in the [language](https://github.com/PHPMailer/PHPMailer/tree/master/language/) folder you'll find numerous (46 at the time of writing!) translations for PHPMailer error messages that you may encounter. Their filenames contain [ISO 639-1](http://en.wikipedia.org/wiki/ISO_639-1) language code for the translations, for example `fr` for French. To specify a language, you need to tell PHPMailer which one to use, like this:
We welcome corrections and new languages - if you're looking for corrections to do, run the [phpmailerLangTest.php](https://github.com/PHPMailer/PHPMailer/tree/master/test/phpmailerLangTest.php) script in the tests folder and it will show any missing translations.
Start reading at the [GitHub wiki](https://github.com/PHPMailer/PHPMailer/wiki). If you're having trouble, this should be the first place you look as it's the most frequently updated.
Examples of how to use PHPMailer for common scenarios can be found in the [examples](https://github.com/PHPMailer/PHPMailer/tree/master/examples) folder. If you're looking for a good starting point, we recommend you start with [the Gmail example](https://github.com/PHPMailer/PHPMailer/tree/master/examples/gmail.phps).
You'll find some basic user-level docs in the [docs](https://github.com/PHPMailer/PHPMailer/tree/master/docs/) folder, and you can generate complete API-level documentation using the [generatedocs.sh](https://github.com/PHPMailer/PHPMailer/tree/master/docs/generatedocs.sh) shell script in the docs folder, though you'll need to install [PHPDocumentor](http://www.phpdoc.org) first. You may find [the unit tests](https://github.com/PHPMailer/PHPMailer/tree/master/test/phpmailerTest.php) a good source of how to do various operations such as encryption.
If the documentation doesn't cover what you need, search the [many questions on Stack Overflow](http://stackoverflow.com/questions/tagged/phpmailer), and before you ask a question about "SMTP Error: Could not connect to SMTP host.", [read the troubleshooting guide](https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting).
There is a PHPUnit test script in the [test](https://github.com/PHPMailer/PHPMailer/tree/master/test/) folder. PHPMailer uses PHPUnit 4.8 - we would use 5.0 but we need to run on PHP 5.4.
If you have git clones from prior to the move to the PHPMailer GitHub organisation, you'll need to update any remote URLs referencing the old GitHub location with a command like this from within your clone: