Posted by R. Berg on January 24, 2001
In Reply to: Return Mail posted by R. Berg on January 23, 2001
: : I agree with Bob, but have totally failed to find any authoritative support for our interpretation (no offense meant, Bob!) in any internet-based source. Can Bob or anyone else cite support for my belief (shared with Bob) that the instruction "send by return mail" requires a prompt response.
: : Thanks again!
: The Oxford English Dictionary (I have the Compact Edition, issued in 1971) provides some historical support. From the entry for "post":
: By return of post (F. par retour du courrier): orig. by return of the 'post' or courier who brought the dispatch (obs.); now, by the next mail in the opposite direction.
: (I've looked in vain for the parallel phrase "return mail" under "mail"; it would be there if the OED were American rather than British.) It seems that to reply by return post once meant writing a hasty note and handing it to the messenger who had brought you a letter. He would then turn his horse around and head back the other way. Among people who pay much attention to language at all, I believe, "return mail" means the next outgoing mail. In the United States, most addresses get a delivery once a day except Sundays and designated holidays, and so replying by return mail to something received on Tuesday would mean sending your response on Wednesday. (Forgive me if I'm explaining too much; I don't know where you are, and postal systems differ.) Replying by return mail to something received on Saturday could be done by posting one's response at a collection box that has a weekend pickup or by sending the response in the next Monday's mail. But it is quite plausible that someone might construe "return mail" as denoting mere reversal of direction, without the implication of urgency-like the carriage return on a typewriter or the ball return in a bowling alley. In other words, if the context for your inquiry is a dispute about whether somebody who replied 18 months late met a requirement (and it does sound as if a legal matter were involved), I'd say the person did not meet the requirement, but his or her failure may have resulted from an honest mistake in misunderstanding the instructions.
Just one more thing: A more recent edition of the OED was published in 1989. Major libraries have it. You might want to consult that edition to see whether "return mail" was added.