Imagine a user that would like to put a form on their website that would allow a website visitor to upload a file and a simple message, which will immediately be emailed (ie
In order to add the file to the email as an attachment, it will need to be stored on the server briefly. It's trivial, though, to place it in a tmp location then delete it after you're done with it.
As for emailing, Zend Mail has a very easy to use interface for dealing with email attachments. We run with the whole Zend Framework installed, but I'm pretty sure you could just install the Zend_Mail library without needing any other modules for dependencies.
With Zend_Mail, sending an email with an attachment is as simple as:
$mail = new Zend_Mail();
$mail->setSubject("My Email with Attachment");
$mail->addTo("foo@bar.baz");
$mail->setBodyText("Look at the attachment");
$attachment = $mail->createAttachment(file_get_contents('/path/to/file'));
$mail->send();
If you're looking for a one-file-package to do the whole form/email/attachment thing, I haven't seen one. But the individual components are certainly available and easy to assemble. Trickiest thing of the whole bunch is the email attachment, which the above recommendation makes very simple.