Thanks to Duong Nguyen for the second user-submitted post on Changing Roundcube Max Attachment Size in Lion Server!
By default, Lion Server’s webmail (Roundcube) has a 5MB max attachment size. The max attachment size is read from php’s “upload_max_filesize” and “post_max_size”. We don’t need to edit php.ini because Lion Server created a .htaccess in Roundcube’s directory that overrides php.ini’s settings.
Please only do this if you are comfortable with the terminal! I start by SSHing to my server as root (or you can open a root terminal).
1. # cd /usr
2. # cd share
3. # cd webmail
4. # vi .htaccess
5. Use your arrow keys to navigate to the end of the 9th and 10th line (“upload_max_filesize” and “post_max_size” respectively)
6. Use your arrow key to highlight the number before M (i.e. 5M)
7. Press i
8. Type 20 (or however large you want) and press delete to remove the 5
9. Press Esc
10. Press :
11. Type x
Now we’re done with the terminal! Restart the Web Server through Server.app, and enjoy your new attachment size!