13 CFR 121.1005: How must a protest be filed with the contracting officer?

A protest must be delivered to the contracting officer by hand, telegram, mail, facsimile, Federal Express or other overnight delivery service, e-mail, or telephone. If a protest is made by telephone, the contracting officer must later receive a confirming letter either within the 5-day period in § 121.1004(a)(1) or postmarked no later than one day after the date of the telephone protest.