Receiving exam results by mail with 郵送
Kanji Explanation: Sending and escorting with 送

Bocchi’s mother confirms with Bocchi that her exam results will be available online.
- ぼっち:
- 「お母さん合格
( 発表( 経験( した?」- “Mom, have you ever been through the experience of waiting for exam results?”
- お母
( さん: - 「もちろん したわよ」
- “Of course!”
- 「お母
( さんの時( は郵送( だったわよ」- “Back in my day, it was sent by mail.”
- “Of course!”
郵送
Key Points
郵送
( = “sent by mail”郵送
( means sending something through the postal service, so here it describes how the exam results were delivered.
お母
( さんの時( は = “back in my day”Here お母
( さんの時( does not mean a single literal moment; it means when it was Mom’s turn.
だった shows the old system or state
郵送
( だった is the past form of 郵送( だ, so Mom is describing what the procedure used to be.That fits the contrast in the scene: Bocchi can check results online, but Mom’s generation had to wait for them to arrive in the mail.
わよ adds gentle emphasis
わよ gives the line a warm, conversational, slightly emphatic tone.
Without it, 郵送
( だった would sound plainer and more neutral.