Yes! This is in fact the first step to undertake when starting to write the proposal. There are over 250,000 donor agencies in the world and most of them have very specific criteria for what types of organizations they fund. If a proposal on land rights in Nepal is sent to a donor who only funds maternal health projects or a donor who only funds projects in Africa, then the proposal will be automatically rejected, no matter how great the proposal.
Organizations should conduct proper research to understand what the donor is looking for before applying. Thematic area, geographic range, typical grant size, type of support, etc. are all important factors to consider when determining to prioritize which donors to approach. Do not waste time sending out mass proposals.
In addition, research the application guidelines of the donor. Find out if there is a format the proposal must follow or a deadline for submission of the proposal.