There you have it:
Easy WP SMTP debug log file
CLIENT -> SERVER: EHLO vasscompany.com
CLIENT -> SERVER: STARTTLS
CLIENT -> SERVER: EHLO vasscompany.com
CLIENT -> SERVER: AUTH LOGIN
CLIENT -> SERVER: [credentials hidden]CLIENT -> SERVER: [credentials hidden]CLIENT -> SERVER: MAIL FROM:<[email protected]>
CLIENT -> SERVER: RCPT TO:<[email protected]>
CLIENT -> SERVER: DATA
CLIENT -> SERVER: Date: Mon, 21 Sep 2020 13:58:18 +0000
CLIENT -> SERVER: To: [email protected]
CLIENT -> SERVER: From: WordPress <[email protected]>
CLIENT -> SERVER: Reply-To: [email protected]
CLIENT -> SERVER: Subject: VASS Formulario de contacto
CLIENT -> SERVER: Message-ID: <[email protected]>
CLIENT -> SERVER: X-Mailer: PHPMailer 6.1.6 (https://github.com/PHPMailer/PHPMailer)
CLIENT -> SERVER: MIME-Version: 1.0
CLIENT -> SERVER: Content-Type: text/plain; charset=UTF-8
CLIENT -> SERVER: Content-Transfer-Encoding: 8bit
CLIENT -> SERVER:
CLIENT -> SERVER: De: Héctor de Prada González [email protected]
CLIENT -> SERVER:
CLIENT -> SERVER: Empresa: AA
CLIENT -> SERVER: Teléfono: 664471232
CLIENT -> SERVER: País: Espa?a
CLIENT -> SERVER:
CLIENT -> SERVER: Cuerpo del mensaje:
CLIENT -> SERVER:
CLIENT -> SERVER: asda da dasd asdas dasd
CLIENT -> SERVER:
CLIENT -> SERVER: —
CLIENT -> SERVER:
CLIENT -> SERVER: Este mensaje se ha enviado desde un formulario de contacto en VASS (https://vasscompany.com)
CLIENT -> SERVER:
CLIENT -> SERVER: .
SMTP ERROR: DATA END command failed: 554 5.2.0 STOREDRV.Submission.Exception:SendAsDeniedException.MapiExceptionSendAsDenied; Failed to process message due to a permanent exception with message Cannot submit message. 0.35250:64010000, 1.36674:0A000000, 1.61250:00000000, 1.45378:02000000, 1.44866:1E230000, 1.36674:0E000000, 1.61250:00000000, 1.45378:23230000, 1.44866:D0010000, 16.55847:C1100000, 17.43559:0000000024020000000000000000000000000000, 20.52176:140F3F8D0B00F01F00000000, 20.50032:140F3F8D7B17F01F0A009A30, 0.35180:08000000, 255.23226:8SMTP Error: data not accepted.CLIENT -> SERVER: QUIT
SMTP ERROR: QUIT command failed: B470000, 255.27962:0A000000, 255.27962:0E000000, 255.31418:02013866, 0.35250:0A006632, 1.36674:0A000000, 1.61250:00000000, 1.45378:02000000, 1.44866:46000000, 1.36674:32000000, 1.61250:00000000, 1.45378:4B000000, 1.44866:01000000, 16.55847:B2000000, 17.43559:00000000A0030000000000002900000000000000, 20.52176:140F3F8D0B001010A7470000, 20.50032:140F3F8D7B17000003002600, 0.35180:AC470000, 255.23226:0A007632, 255.27962:0A000000, 255.27962:32000000, 255.17082:DC040000, 0.27745:03003600, 4.21921:DC040000, 255.27962:FA000000, 255.1494:0A004100, 0.38698:05000780, 0.37692:01000000, 0.44092:0F010480, 0.41232:01000000, 0.60208:0F010480, 0.37136:00000000, 0.34608:05000780, 0.55056:05000780, 0.42768:00000000, 0.56112:05000780, 0.52807:05000780, 7.36354:010000000000010905000780, 4.33016:DC040000, 7.40748:010000000000010B05000780, 7.57132:000000000000000000000000, 1.63016:32000000, 4.39640:DC040000, 8.45434:181434369F52884980A62ECE6BC5D92F05000780, 5.10786:0000000031352E32302E333339312E3031313A564931503138394D42303330323A64386536303435312D383562302D343438652D613433622D38373433353061313834363400384000000000, 7.51330:C4B0F165365ED80805000780, 0.39570:00000000, 1.55954:0A000000, 0.49266:02000000, 1.33010:0A000000, 2.54258:00000000, 0.40002:07000000, 1.56562:00000000, 1.64146:32000000, 1.33010:32000000, 2.54258:DC040000, 255.1750:42440000, 255.31418:0A00D030, 0.22753:0B00CD0E, 255.21817:DC040000, 0.64418:0A00EB30, 4.39842:DC040000, 0.41586:4C440000, 4.60547:DC040000, 0.21966:0300F40F, 4.30158:DC040000 [Hostname=VI1P189MB0302.EURP189.PROD.OUTLOOK.COM]
221 2.0.0 Service closing transmission channel