What's a formal and polite way to tell somebody "if you had told me in advance?" I'm writing an e-mail to someone who asked a month ago for a copy of a document delivered by postal mail. Turns out a pdf sent by email would've been just fine.
So I want to say "If you had told me in advance a pdf was just enough I would've send it immediately a month ago" without stepping on anybody's toes.
A formal (and not too confrontational) way of stating your thought would be: "I wish I'd been made aware.".....or "If I'd only been made aware".
Both of these, of course, have the effect of "transferring the blame" to the recipient of your message....which I assume is the intention of your words. :-)
"Had I known" has the necessary intent without really placing blame on anyone in particular.
You could turn it around, particularly if the client is a sensitive type or the delay has cause some problem (and you don't want to be seen to be transferring the blame as noted in Michael Scott's answer). Something along the lines of "I neglected to ask if an electronic version would have suited your needs."
