〜をもって

本日(ほんじつ)をもって受付(うけつけ)を終了(しゅうりょう)します。

Honjitsu o motte uketsuke o shūryō shimasu.

Applications close as of today.

The first sense of をもって is a cut-off point, for formal notices

書面(しょめん)をもってご連絡(れんらく)いたします。

Shomen o motte gorenraku itashimasu.

We will contact you in writing.

The second is by means of — the written で

この組(くみ)の中(なか)では最(もっと)もよく使(つか)われます。

Kono kumi no naka de wa mottomo yoku tsukawaremasu.

It is the most used of this set.

It appears in notices, announcements and citations, hence two flames