previous letter; last letter
Used in correspondence to refer to one's own previous letter or message. Common in formal or business contexts.
前便にてお知らせした通り、会議は延期となりました。
As I informed you in my previous letter, the meeting has been postponed.
前
If you have any questions about the content of my last letter, please let me know.
Compound of 前 (previous) and 便 (mail, correspondence). The reading ぜんびん follows standard on'yomi.