2021-01-22 05:46:28 CLIENT -> SERVER: EHLO portalcucicba.com.ar 2021-01-22 05:46:28 CLIENT -> SERVER: STARTTLS 2021-01-22 05:46:29 CLIENT -> SERVER: EHLO portalcucicba.com.ar 2021-01-22 05:46:29 CLIENT -> SERVER: AUTH LOGIN 2021-01-22 05:46:29 CLIENT -> SERVER: bWlnQHBvcnRhbGN1Y2ljYmEuY29tLmFy 2021-01-22 05:46:29 CLIENT -> SERVER: MTIzbmlhZ2E= 2021-01-22 05:46:31 SMTP ERROR: Password command failed: 535 5.7.8 Error: authentication failed: UGFzc3dvcmQ6 2021-01-22 05:46:31 SMTP Error: Could not authenticate. 2021-01-22 05:46:31 CLIENT -> SERVER: QUIT 2021-01-22 05:46:31 SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting