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(かあ)さん合格(ごうかく)発表(はっぴょう)経験(けいけん)した？」; “Mom, have you ever been through the experience of waiting for exam results?”; Literal: “Mom, did you experience acceptance-result announcements?”
お母(かあ)さん:: 「もちろん　したわよ」; “Of course!”; 「お母(かあ)さんの時(とき)は郵送(ゆうそう)だったわよ」; “Back in my day, it was sent by mail.”; Literal: “In Mom's time, it was postal delivery.”

郵送(ゆうそう) marks the method of delivery as being sent through the postal service, as opposed to Bocchi’s results being accessible electronically.

Key Points

1郵送(ゆうそう) = “sent by mail”

郵送(ゆうそう) means sending something through the postal service, so here it describes how the exam results were delivered.

2お母(かあ)さんの時(とき)は = “back in my day”

Here お母(かあ)さんの時(とき) does not mean a single literal moment; it means when it was Mom’s turn.

3だった shows the old system or state

郵送(ゆうそう)だった is the past form of 郵送(ゆうそう)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.

4わよ adds gentle emphasis