This is exactly the same as the body of a regular letter.

In Dutch and German, the word brief refers to a regular letter.

"How much does it cost to send a regular letter to Korea?"

"What might we expect to find here, if this were a regular letter, for instance?"

People are still going to be sending regular letters.

His regular letters to his parents were intercepted by the government and confiscated.

In the weeks that followed, regular letters from Jason continued to reassure the king that he been right to send his brother into the field.

It was written in neat, and regular letters.

Applications should be sent in a regular letter or business envelope by regular mail.

The two generals remained close friends, exchanging regular letters until Eichelberger's death in 1961.