Installing IMAP functions for PHP on Debian: an Agaric saga

Fatal error: Call to undefined function imap_open() in /var/www/drupal-5/modules/contributed/mailhandler-5.x-1.1.tar/mailhandler/mailhandler.module on line 16

Probably the Debian package php-net-imap which installs:

http://pear.php.net/package/Net_IMAP

(no useful documentation there) just doesn't do it.

So:

http://us.php.net/manual/en/ref.imap.php

Do it.

Update:

Fascinating.

Searching for
php imap debian
brought nothing useful, just that silly pear package and some defunct Debian and Ubuntu packages.

However, searching for:
php imap c-library debian

seems to have brought up exactly what we need:

http://packages.debian.org/unstable/web/php5-imap

Let's apt-get install php5-imap, then.

The whole "unstable" thing is a little scary.

More scary!

Libc-client earlier than version 2002d (and development versions of?? 2003) included an unofficial and no longer maintained patch to support Maildirs. By default Maildirs were not used by uw-imapd or ipopd, but if you have changed your system configuration or other installed programs depend on libc-client then upgrading may result in broken mail handling.

Do you want to continue installing a libc-client without Maildir support? ??
Continue installing libc-client without Maildir support?

<Yes> <No>

To heck with Maildir support! Onward!

Unpacking php5-imap (from .../php5-imap_5.2.0-8+etch7_i386.deb) ...
Setting up mlock (2002edebian1-13.1) ...
Setting up libc-client2002edebian (2002edebian1-13.1) ...

Setting up php5-imap (5.2.0-8+etch7)

So it would seem that to actually use this we have to go back to the PHP-IMAP instructions and do this:

To get these functions to work, you have to compile PHP with --with-imap[=DIR], where DIR is the c-client install prefix. From our example above, you would use --with-imap=/usr/local/imap-2000b. This location depends on where you created this directory according to the description above.

And possibly:

Note: Depending how the c-client was configured, you might also need to add --with-imap-ssl=/path/to/openssl/ and/or --with-kerberos=/path/to/kerberos into the PHP configure line.

I really have to learn where Debian actually puts things. It's surely somewhere standard that everyone should know but would it kill the install script to just tell me?