How can I change the maximum attachment size for Webmail?

This is actually not a limitaton of Webmail/SquirrelMail, but of PHP.

You will need to add/edit "

upload_max_filesize

" in

/etc/php.ini

OS X Server does not come with a

php.ini

file in place (it relies on the default values compiled into PHP).

If you haven't done so already, just create a new

php.ini

file and add:

upload_max_filesize = 5M

(or whatever size you need)

When done editing issue:

sudo /usr/sbin/apachectl graceful restart

Alternatively you can copy the supplied

/etc/php.ini.default

to

/etc/php.ini

and use it as starting point.

I do recommend to start with a new file though. Over time you can just add any parameters you want to differ from the defaults, while still keeping a clean and readable

php.ini