郵便 and 宅配: postal mail and delivery to a home
Separate sending methods, delivery locations, requests, and completion.
Sending by post
郵便 (ゆうびん) means postal mail. 「書類を郵便で送りました」 says documents were sent by post.
「郵便が届きました」 reports mail arriving. Distinguish a sending method from a context referring to the delivered items.
Delivery to a home
宅配 (たくはい) means delivery of goods to a home or similar destination. 「宅配を頼みました」 means requesting delivery.
「夕食を宅配で注文しました」 means ordering dinner for delivery. The term can occur with food, not just documents or parcels.
Names versus outcomes
Do not divide 郵便 and 宅配 rigidly by company name based on the words alone. Check specific service information for names and accepted items.
「宅配を頼みましたが、まだ届いていません」 says delivery was requested but has not arrived. Request and receipt are separate stages.
Does 「宅配を頼みました」 establish receipt of the goods?
Show the answer and why
No. It reports requesting delivery; receipt is separate.