Here is FAQ #10 on the DoDMERB website: It does not offer email as an option. (but I have heard of many doing so.)
My DS chose to send the remedial docs via FEDEX overnight to allow for traceability.
10. Will you allow me to fax documents pertaining to my medical status to you?
You may fax documents pertaining to your medical status to DoDMERB.
We do ask however, if the total number of pages exceeds 15, that you mail those instead of faxing. DoDMERB has limited ability to receive faxes and faxes exceeding 15 pages could delay our ability to process your documents as quickly as possible.
Please note: If you fax documentation to DoDMERB, you DO NOT need to mail the same document(s).
Our fax number is: 719-333-3578. Our mailing address is: DoDMERB, 8034 Edgerton Drive, Suite 132, United States Air Force Academy, CO 80840-2200. DoDMERB has the capability to receive all types of mail deliveries, (i.e., US Postal Service, FedEx, UPS, etc.).