Sometimes finishing a grant application is so consuming it is easy to overlook some necessary factors buried in the fine print.
Agencies use either receipt dates or postmarks.
Postmarks require hand canceling and overnight parcels should be out by noon the previous day, if it absolutely, positively has to be there. These usually are to accommodate scanning and if they specify 10 cpi and you use 10 pt your proposal will be thrown away. Figures and charts must be black and white. Even if multiple copies are required an agency may make additional copies. If a figure does not make sense without color it will not make sense to reviewers.