FAR 15.208(a) says offerors are responsible for submitting proposals, revisions, and modifications so as to reach the Government office designated in the solicitation by the time specified, using a transmission method authorized by the solicitation, such as regular mail, electronic commerce, or facsimile. FAR 52.215-1, when in the solicitation, repeats that the proposal must reach that designated office by the specified time unless the solicitation permits another method. FAR 52.212-1(b), when it applies, tells offerors to submit signed and dated offers to the office specified in the solicitation at or before the exact time specified.
Copy the address, email, portal URL, file-size cap, and permitted formats from Section L or the commercial addendum, including the latest amendment. A contracting officer’s informal email is not a substitute if the instructions name a portal. An IPP or WAWF line is post-award invoicing, not the bid destination, as Module 4 taught.
Preserve what the receiving system actually issued: a portal confirmation number and timestamp, a Government email that states the file was received at the designated mailbox, or a carrier receipt showing delivery to the named office. Your “sent” folder, a delivery receipt from your mail server, or an AsherGate upload is not the same as receipt at the designated Government office. FAR 15.208(c) lists acceptable evidence of time of receipt at the Government installation as that installation’s time/date stamp, other documentary evidence the installation maintains, or oral testimony or statements of Government personnel. Do not assume your outbound timestamp will be used.