Change email password without logging in
If you would like your pop users to be able to change their own email passwords without having to login to the control panel, simply give them this link:
Where www.domain.com is either your domain, hostname, or IP address.
More information on this function and how you can use it via API can be found Here
There is also a DA plugin that also gives email users the ability to change their passwords, and vacation messages, and show them their email stats, all in once place:
For automated vacation messages changes by email users, it can be implemented via API here, or just use the plugin above: http://www.directadmin.com/forum/showthread.php?t=13112
A squirrelmail plugin has been created which allows interaction with DirectAdmin showing usage, as well as the ability to change the password and vacation message: