Downloading attachments through SquirrelMail

I’m away from my home computer and am attempting to download several files (3-9mb each) from a client through SquirrelMail. I had no problem with the smaller of those files, but I’m getting an error message (“attempt to load accessing URL: … failed”) when attempting to dowload the larger ones (6-9mb).

Is there a cap on the size of files that can be downloaded through SquirrelMail? If so, is there any way for me to retrieve these files short of going home and doing it through my non-browser email client?