[drupal-devel] [wanted] mail queue

[Nedjo Rogers]

> As you said, proper mailing is hard.  Hence the need to make this a
> specialized service and to extract this from the individual modules.
> Hence my call for people with experience, or for people willing to
> learn more about this.  I don't expect this to be implemented
> overnight, but it would be nice if some people could explore our
> options, see what other projects have done, prototype some code, etc.

I agree we need a separate mail.inc.  This is partly just because mailing
needs go far beyond what the user module needs.  The user module should be
one of a number of front ends.

Some potential approaches are implemented in the mail.module, and that might
be a better starting point for discussions than the current user_mail()
function.

Mail.module implements a custom mail_send() function, which handles mail
format, priority, attachments, character set, encoding, etc. as well as
testing for send success.  The sending itself is handled by a LGPL PHP
mailing class, activeMailLib, which was introduced into the module through a
patch by Dublin Drupaller in order to implement attachment support and other
functionality.

I would look to a mail.inc component to handle:

1. Mail sending.  Accept a $mail argument with the following properties:

* to (string or array)
* from (string)
* format (string: html or plain text)
* subject (string)
* priority (int)
* receipt (boolean)
* character set
* encode
* files/attachments (array)

2. System-wide mail-related permissions and configuration options

a. permissions, possibly:

'email users'
'email users in own role'
'email nonusers'

b. default sending options (format, character set, etc.).

In mail.module, this is currently implemented through mail_settings(), which
provides system defaults, and mail_form_elements($node), which provides a
node editing form group for overriding the system defaults.

3. Queuing

4. Bounce tracking and handling

To implement this approach, we could:

* start with applicable mail.module functions
* for mail handling, use activeMailLib (or another candidate), or
(preferably) adapt it to Drupal coding approaches.

Queuing and bounce tracking/handling would be added later.

Thoughts?

Nedjo