I sent a postcard to my friend.

Could you tell me your postal code?

I sent you a postcard.

I sent important documents by registered mail.

There is not a single letter in my mailbox.

Please put the letter in the post office box.

I posted a letter in the mailbox.

There is a planned blackout tonight, so please come home early.

He is systematically advancing his work.

We will hold a meeting to make a new business plan.