11. FAQ

11.1 How can I diagnose blank pages?

Under some circumstances, a page request can result in nothing more than a blank page. In most cases, this happens after the installation of a plugin, but it can happen elsewhere as well. This problem is typically caused by fatal PHP errors that are simply not being shown on screen.

You can find those errors by looking in your web server log file. The location of that file will be different on some machines, but one example is /var/log/httpd/error_log.

Alternatively, you can tell PHP to display the errors on screen in one of a few ways described below (remember to turn them off again if you are doing this in a production environment):

• Change the error reporting settings in php.ini (remember to restart the web server after you make changes to php.ini):

        display_errors=On
        error_reporting=E_ALL
      
  

• Change the error reporting settings just for SquirrelMail by adding the following lines into an .htaccess file in the main SquirrelMail directory (this is an Apache web server feature that also requires that you have at least "AllowOverride Options" in the <Directory> section that applies to your SquirrelMail installation within the Apache configuration file).

        php_flag display_errors On
        php_value error_reporting E_ALL
      
  

• Install the SquirrelMail Debugger plugin

Note that if you still have trouble seeing errors on screen, make sure you have not overridden the error reporting settings in your Apache configuration file or in another .htaccess file or custom SquirrelMail plugin, etc.

Some more common causes of blank pages are:

• You installed a new plugin but forgot to install one of its dependencies (such as the Compatibility plugin) or apply a required patch. Please carefully consult all the documentation files that came with your new plugin, including its README and INSTALL files.
• You are attempting to view a folder with a very large number of messages in it (perhaps as many as 10,000). In this case, you may hit the maximum PHP execution time limit or maximum memory limit. If you find such errors, you may want to review our optimization tips or our performance hints.
• You have installed SquirrelMail for the first time and it does not work at all - even the configuration test page and the login page come up blank. This can be caused by the lack of session support in PHP (which SquirrelMail requires). See the PHP session extension installation manual.

11.2 How do I migrate mails between servers?

Here are several options for your consideration:

• If you are able to access your IMAP server using means other than SquirrelMail (that is, if your server's IMAP or IMAP-SSL ports are available from your location), it is recommended that you use a dedicated migration tool, such as imapsync or IMAPCopy. IMAP copying/migration tools are available for various platforms, so if neither of these two fits your requirements, use a search engine to find something to match your setup.

• If you are able to use another IMAP client (such as Thunderbird) to access mail on your servers, you can add both the new and old accounts to it and drag and drop messages between the old and new accounts. Note that this requires each user to set up and migrate their own messages - you cannot migrate multiple user accounts automatically using this method.

• If you are migrating away from a POP3 server, you can use the Mail Fetch plugin (bundled with SquirrelMail). It'll transfer mail from your POP3 inbox to your SquirrelMail installation, but it won't handle folders. Note that this requires each user to set up and migrate their own messages; if you need to automate the process for multiple users, use another tool or create your own script to add the needed SquirrelMail settings for the Mail Fetch plugin to each user's SquirrelMail preferences.

• If you're migrating away from SquirrelMail you can use the Archive Mail plugin to download mails from the server, but there might not be an easy way to upload those mails to the new server.

When using tools other than SquirrelMail, you'll probably need to make sure that the ports needed to access the servers are open. The system administrator may need to help you if you don't have the access or ability to open them yourself (or if any of the systems you are working with use any non-standard ports).

The standard ports to use for clients and/or migration tools are:

11.3 How do I migrate address books between servers?

Use the SquirrelMail Addressbook Import-Export plugin.