SquirrelMail - Webmail for Nuts!

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 TT TT    | | | |( )  _  ( )  ZZZ     TT  TT  
 TT  TT   | |_| || | ( ) | |  Z ZZ     TTTT   
 TT  TT   |  _  || | | | | | Z  ZZ      TT    
 TT  TT   |_| |_|| (_/ \_) |ZZZZZZZ    TTTT   
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Visit Preferences to set your user name

=== Uploading the attachment to the server ===

'''Limitations in PHP'''

PHP sets limits on the maximum files size when uploading files to the server.  To change this limit, you need to edit the {{php.ini}} configuration file. The values you will need to increase or decrease are:
*[http://php.net/manual/en/ini.core.php#ini.memory-limit memory_limit]
*[http://php.net/manual/en/ini.core.php#ini.post-max-size post_max_size]
*[http://php.net/manual/en/ini.core.php#ini.upload-max-filesize upload_max_filesize]

The values can be set in bytes (1,048,576 per MB) or they can be set by MB by appending the value with an "M", i.e. 8M.

To upload large files, {{post_max_size}} must be larger than {{upload_max_filesize}}. If memory limit is enabled by configure script, {{memory_limit}} also affects file uploading. Generally speaking, {{memory_limit}} should be larger than {{post_max_size}}. [http://php.net/manual/en/configuration.php#ini.post-max-size]

There is also more information to be found in the PHP documentation about [http://php.net/features.file-upload handling file uploads].

'''Limitations in the web server'''

The HTTP server may add further restrictions on the file upload size:
* Apache: You can restrict maximum file size using [http://httpd.apache.org/docs/mod/core.html#limitrequestbody LimitRequestBody] directive. Search for {{/etc/httpd/conf.d/php.conf}} and comment out {{!LimitRequestBody}}. Restart Apache after editing the configuration and you will be able to attach file with sizes over 0,5 MB again.

<code>
<Files *.php>
    SetOutputFilter PHP
    SetInputFilter PHP
#    LimitRequestBody 524288
</Files> 
</code>

'''Limitation in web proxies'''

Pay attention if you use any proxy server like Squid. In Squid, you need to change the {{request_body_max_size}} (the default is 1 MB), e.g: {{request_body_max_size 10 MB}}

In some versions of Squid this is called {{request_size}} rather than {{request_body_max_size}}.

=== Sending the mail with the attachment ===

You should also take into account limits for your MTA software:
* Courier-MTA: {{showconfig}} or {{/etc/courier/sizelimit}} - default 10MBytes
* Postfix: a configuration parameter called {{message_size_limit}} in the file {{/etc/postfix/main.cf}} sets the maximum size (in bytes) of the entire message - default: 10240000 - i.e. approximately 10MBytes
* Qmail-MTA:  a file in {{/var/qmail/control}} called databytes. The file contains one line that represents the max size of attachments in bytes.
* Sendmail: option !MaxMessageSize, usually unset; can be changed in mc file {{define(`confMAX_MESSAGE_SIZE',`5242880')dnl}}
*hMail: !Max message size (KB) in Settings > Protocols > SMTP

----

=== Comments ===

You may be able to keep your users from submitting attachments that are too large by implementing this piece of HTML code: 
{{<input type="hidden" name="MAX_FILE_SIZE" value="1000">}}
NOTE: It may not work with all browsers.  This, of course, begs the question "Which browsers does it work with?"    Please post your findings here:

* Konqueror seems not to obey this limit.
* Mozilla seems not to obey this limit.
* Microsoft Explorer seems not to obey this limit.
So, does this work or is the code no good?
: '''kink:''' I think this is an error in the PHP documentation, because I couldn't find a single browser which does something with this limit.
: '''tokul:''' Firefox (1.0 Debian Sarge) follows it, but interface can't rely on restriction that is controlled by the end user.

Related bug: [http://sourceforge.net/tracker/index.php?func=detail&aid=597206&group_id=311&atid=423679 SquirrelMail bug 597206]

Probably the problem with memory starvation with big files is not a !SquirrelMail problem but a PHP problem, seems to be solved since PHP 4.2.0, look at: [http://bugs.php.net/bug.php?id=17606 PHP bug 17606] (not sure anyway).

Problem noted on Red Hat 8.0/9.0 with Apache 2.0.x, the error "Requested content-length of 670955 is larger than the configured limit of 524288" was occurring under Apache and a "Page not found" would appear in the browser. Trying the above settings made no change with PHP, but on Red Hat 8.0/9.0 there is an additional PHP configuration file, {{/etc/httpd/conf.d/php.conf}, and increasing the number on the line {{!LimitRequestBody 524288}} solves the issue.

Gentoo Linux has a file like the above mentioned where the limits are set, the file is {{/etc/apache2/conf/modules.d/70_mod_php.conf}}.

As a side note, check the maximum execution time in {{php.ini}}. Very large attachments may take longer than the 30 seconds allowed. Symptoms may be found by looking at the httpd error log and seeing "httpd in free(): warning: recursive call" yet the httpd does not core fault and die altogether. For a 10 MB file attachment I set execution time to 120 seconds.

Gentoo Linux - Update - Actually, I did not find the {{*mod_php.conf}} file in Gentoo Linux had any of the above information.  I modified the {{/etc/php4/php.ini}} file as directed.  Though, I did find a link to this file in the Apache directory under {{/etc/apache/conf/php.ini}}.

The file that needs to be adjusted in the Red Hat 9 configuration of Apache 2.x is in {{/etc/httpd/conf.d/php.conf}}. The paths given above are inaccurate, at least for Red Hat 9. This solves the Apache interference, but is not the only limiter on large files.

Gentoo Linux: After raising the above mentioned values to 10M in {{php.ini}}, you ''do'' need to change {{!LimitRequestBody}} in {{/etc/apache2/conf/modules.d/70_mod_php.conf}}! I put mine to {{2097152}}, which is equivalent to 2M. This way, I can limit ''each'' attachment file size to 2M while the message size is 10M.

IMPORTANT: You must restart Apache before any changes take effect.

Summary of change:
Add document to category:

Editing AttachmentSize