Not sent
That did not go through.
Your message was not delivered, and we would rather tell you than let you assume it arrived.
Email us instead — it always works
Three lines is plenty. What you are shipping, what keeps breaking, and what you have already tried.
Why this happens
Usually one of two things: the message tripped a spam check, or our mail transport is temporarily unavailable. Either way the fault is ours to fix, not something you did wrong, and the address above bypasses all of it.