ゆうそう郵送yuusou
1.

The act of sending items through the postal service, typically involving the use of envelopes or packages.

2.

A process by which documents or goods are dispatched to a recipient via postal channels, often associated with a fee for delivery.

3.

The method of transferring correspondence or parcels by means of the postal system, which may include tracking and delivery confirmation options.

Example:

計算書は四半期ごとに郵送されます。