E-mail submissions are fine, however a few things bug me about attachments;
Even in these enlightened broadband days, it’s no fun to see a 10MB attachment crawl in from someone you don’t know. I would advise a simple CV attachment with a link to your website where files may be downloaded if necessary. Failing that, a note indicating files are available on request.
Nothing turns me off an application quicker than the prosumprion on the part of the applicant that I want to see their entire portfolio right now.
Don’t assume that the person receiving the job application mail will have access to software capable of opening propreitary file formats (3DSmax, Maya etc.). While such software may be available around the office, it takes a bit of effort for an admin person to fire it up, transfer your files etc.
Always stick to universal interchange formats (jpeg, avi etc.).
My life would be easier if people followed the above!