Image attachment, maximum size?

I've have several clients tell me they can't send the Pet Info form... It just stalls on them.  I think the common denominator is the image attachment. I think they could be attaching an image that is too big.  How big is too big? What is the maximum/appropriate file size of an image attachment so the form will actually go through?  I'd like to insert a "maximum file size" notice next to the image attachment fields.

Thanks, Julie

You can upload 1GB, but do note that this space is used in your account and you may get the out of space message, the default max size limit is 1MB, but you can change it by following this guide: http://www.jotform.com/help/33-Changing-the-Upload-Size-Limit.