What could break Vesta Cp, email?

Question

Email

Worth vesta / centos - the sender program (generates a letter) works correctly, tested on different servers. This server produces such trouble.
I updated the message, didn't help.
The letter comes like this.

Received: from 24.flagman.ru (212.193.229.252) by gr.mmsir.ru; (envelope-from <[email protected]>)
Return-Path: <[email protected]>
Message-ID: <[email protected]>
Date: Thu, 08 Aug 2019 16:40:49 +0000
Subject: =?utf-8?Q?=D0=9F=D0=BE=D0=B4=D1=82=D0=B2=D0=B5=D1=80=D0=B4?=
 =?utf-8?Q?=D0=B8=D1=82=D0=B5_=D0=B0=D0=BA=D1=82=D0=B8?=
 =?utf-8?Q?=D0=B2=D0=B0=D1=86=D0=B8=D1=8E_=D1=81=D0=B5?=
 =?utf-8?Q?=D1=80=D0=B2=D0=B5=D1=80=D0=B0?=
From: [email protected]
Reply-To: [email protected]
To: [email protected]
MIME-Version: 1.0
Content-Type: multipart/alternative;
 boundary="_=_swift_v4_1565282449_d733367c991d4bda4a1610e54342baa3_=_"
X-Sender: [email protected]
X-Receiver: [email protected]
X-Mw-Mailer: SwiftMailer - 5.4.x


--_=_swift_v4_1565282449_d733367c991d4bda4a1610e54342baa3_=_
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable

Answer 1

What's broken in the mail?