郵便局に行って

go to the post office and

→ 郵便局
phrase Rare #29,441
go to the post office and 行って is the te-form of 行く (to go). It connects this action to what follows, and can also be used as a request meaning “go to the post office.”
JA: 郵便局に行って、荷物を送ります。
EN: I’ll go to the post office and send a package.

切手を買いに郵便局に行ってきた

I went to the post office to buy stamps.

郵便局に行って新しい郵便番号何番聞いてきて

Go to the post office and ask what the new ZIP code is.