That's wider than nearly every website's width. It would break the formatting. We had that problem before - - -
Don't remember when, exactly, but we began allowing file uploads, storing them on OUR server, some time back... but we had to restrict the hosting of files to make sure we had enough space on the server... hence the file size restrictions. Currently they are set too:
Max. File Size: 500kb
Max. Width: 800 Pixels
Max. Height: 600 Pixels.
With this new server we have far more efficiency, speed, but LESS storage space... so doubtful we can increase the current size restrictions.
I haven't messed with it a lot... it's possible we have the forum software itself conflicting with an added module we included to allow hosting photos and displaying them within messages. Perhaps one or the other is 'overruling' the other? I don't know, I'll check. - JamesJM