请教8老师及各位：H1B email notice of approval 到真正收到 approval notice （I-7

7/24 USCIS emailed the employer that the H-1B has been approved and the Approval Notice will follow in mail.
可是到现在8/3雇主还没收到信（然后才能转给我）。会不会是寄丢？平时这两步之间 要多久？谢谢。