Test Email Not Working

  • Resolved dtrewin

    (@dtrewin)


    5 months, 3 weeks ago

    Does anyone know why the test email is not working?

    Versions:
    WordPress: 6.8.3
    WordPress MS: No
    PHP: 8.1.33
    WP Mail SMTP: 4.7.1

    Params:
    Mailer: smtp
    Constants: No
    ErrorInfo: SMTP Error: Could not authenticate.
    Host: smtp.office365.com
    Port: 587
    SMTPSecure:    tls
    SMTPAutoTLS:bool(true)
    SMTPAuth:bool(true)

    Server:
    OpenSSL: OpenSSL 1.1.1w 11 Sep 2023

    Debug:
    Email Source: WP Mail SMTP Mailer: Other SMTP SMTP Error: Could not authenticate.

    SMTP Debug:
    2025-12-05 11:52:14 Connection: opening to smtp.office365.com:587, timeout=30, options=array()
    2025-12-05 11:52:14 Connection: opened
    2025-12-05 11:52:14 SERVER -> CLIENT: 220 FR3P281CA0123.outlook.office365.com Microsoft ESMTP MAIL Service ready at Fri, 5 Dec 2025 11:52:14 +0000 [08DE33A6974165C4]
    2025-12-05 11:52:14 CLIENT -> SERVER: EHLO jc-plumbing.co.uk
    2025-12-05 11:52:14 SERVER -> CLIENT: 250-FR3P281CA0123.outlook.office365.com Hello [82.165.90.172]250-SIZE 157286400250-PIPELINING250-DSN250-ENHANCEDSTATUSCODES250-STARTTLS250-8BITMIME250-BINARYMIME250-CHUNKING250 SMTPUTF8
    2025-12-05 11:52:14 CLIENT -> SERVER: STARTTLS
    2025-12-05 11:52:14 SERVER -> CLIENT: 220 2.0.0 SMTP server ready
    2025-12-05 11:52:14 CLIENT -> SERVER: EHLO jc-plumbing.co.uk
    2025-12-05 11:52:14 SERVER -> CLIENT: 250-FR3P281CA0123.outlook.office365.com Hello [82.165.90.172]250-SIZE 157286400250-PIPELINING250-DSN250-ENHANCEDSTATUSCODES250-AUTH LOGIN XOAUTH2250-8BITMIME250-BINARYMIME250-CHUNKING250 SMTPUTF8
    2025-12-05 11:52:14 CLIENT -> SERVER: AUTH LOGIN
    2025-12-05 11:52:14 SERVER -> CLIENT: 334 VXNlcm5hbWU6
    2025-12-05 11:52:14 CLIENT -> SERVER: [credentials hidden]
    2025-12-05 11:52:14 SERVER -> CLIENT: 334 UGFzc3dvcmQ6
    2025-12-05 11:52:14 CLIENT -> SERVER: [credentials hidden]
    2025-12-05 11:52:20 SERVER -> CLIENT: 535 5.7.139 Authentication unsuccessful, SmtpClientAuthentication is disabled for the Tenant. Visit https://aka.ms/smtp_auth_disabled for more information. [FR3P281CA0123.DEUP281.PROD.OUTLOOK.COM 2025-12-05T11:52:20.027Z 08DE33A6974165C4]
    2025-12-05 11:52:20 SMTP ERROR: Password command failed: 535 5.7.139 Authentication unsuccessful, SmtpClientAuthentication is disabled for the Tenant. Visit https://aka.ms/smtp_auth_disabled for more information. [FR3P281CA0123.DEUP281.PROD.OUTLOOK.COM 2025-12-05T11:52:20.027Z 08DE33A6974165C4]
    SMTP Error: Could not authenticate.
    2025-12-05 11:52:20 CLIENT -> SERVER: QUIT
    2025-12-05 11:52:20 SERVER -> CLIENT: 221 2.0.0 Service closing transmission channel
    2025-12-05 11:52:20 Connection: closed
    SMTP Error: Could not authenticate.

    Versions:
    WordPress: 6.8.3
    WordPress MS: No
    PHP: 8.1.33
    WP Mail SMTP: 4.7.1

    Params:
    Mailer: smtp
    Constants: No
    ErrorInfo: SMTP Error: Could not authenticate.
    Host: smtp.office365.com
    Port: 587
    SMTPSecure:tls
    SMTPAutoTLS:bool(true)
    SMTPAuth:bool(true)

    Server:
    OpenSSL: OpenSSL 1.1.1w 11 Sep 2023

    Debug:
    Email Source: WP Mail SMTP Mailer: Other SMTP SMTP Error: Could not authenticate.

    SMTP Debug:
    2025-12-05 11:52:14 Connection: opening to smtp.office365.com:587, timeout=30, options=array()
    2025-12-05 11:52:14 Connection: opened
    2025-12-05 11:52:14 SERVER -> CLIENT: 220 FR3P281CA0123.outlook.office365.com Microsoft ESMTP MAIL Service ready at Fri, 5 Dec 2025 11:52:14 +0000 [08DE33A6974165C4]
    2025-12-05 11:52:14 CLIENT -> SERVER: EHLO jc-plumbing.co.uk
    2025-12-05 11:52:14 SERVER -> CLIENT: 250-FR3P281CA0123.outlook.office365.com Hello [82.165.90.172]250-SIZE 157286400250-PIPELINING250-DSN250-ENHANCEDSTATUSCODES250-STARTTLS250-8BITMIME250-BINARYMIME250-CHUNKING250 SMTPUTF8
    2025-12-05 11:52:14 CLIENT -> SERVER: STARTTLS
    2025-12-05 11:52:14 SERVER -> CLIENT: 220 2.0.0 SMTP server ready
    2025-12-05 11:52:14 CLIENT -> SERVER: EHLO jc-plumbing.co.uk
    2025-12-05 11:52:14 SERVER -> CLIENT: 250-FR3P281CA0123.outlook.office365.com Hello [82.165.90.172]250-SIZE 157286400250-PIPELINING250-DSN250-ENHANCEDSTATUSCODES250-AUTH LOGIN XOAUTH2250-8BITMIME250-BINARYMIME250-CHUNKING250 SMTPUTF8
    2025-12-05 11:52:14 CLIENT -> SERVER: AUTH LOGIN
    2025-12-05 11:52:14 SERVER -> CLIENT: 334 VXNlcm5hbWU6
    2025-12-05 11:52:14 CLIENT -> SERVER: [credentials hidden]
    2025-12-05 11:52:14 SERVER -> CLIENT: 334 UGFzc3dvcmQ6
    2025-12-05 11:52:14 CLIENT -> SERVER: [credentials hidden]
    2025-12-05 11:52:20 SERVER -> CLIENT: 535 5.7.139 Authentication unsuccessful, SmtpClientAuthentication is disabled for the Tenant. Visit https://aka.ms/smtp_auth_disabled for more information. [FR3P281CA0123.DEUP281.PROD.OUTLOOK.COM 2025-12-05T11:52:20.027Z 08DE33A6974165C4]
    2025-12-05 11:52:20 SMTP ERROR: Password command failed: 535 5.7.139 Authentication unsuccessful, SmtpClientAuthentication is disabled for the Tenant. Visit https://aka.ms/smtp_auth_disabled for more information. [FR3P281CA0123.DEUP281.PROD.OUTLOOK.COM 2025-12-05T11:52:20.027Z 08DE33A6974165C4]
    SMTP Error: Could not authenticate.
    2025-12-05 11:52:20 CLIENT -> SERVER: QUIT
    2025-12-05 11:52:20 SERVER -> CLIENT: 221 2.0.0 Service closing transmission channel
    2025-12-05 11:52:20 Connection: closed
    SMTP Error: Could not authenticate.
Viewing 2 replies - 1 through 2 (of 2 total)
  • rodeboy

    (@rodeboy)

    5 months, 2 weeks ago

    Several people are reporting this now. For me, the test email works if the email address I am sending from is on the same server as the website. However if the client uses MS or whatever to host their emails then the test email fails. This is constant with all my sites, suggesting to me that there is a bug. It was working fine until recently, and none of the settings have been changed. I look forward to an update, or advice on what I’m doing wrong!!

    Plugin Support Patrick

    (@paddyam)

    5 months, 2 weeks ago

    Hi @dtrewin and @rodeboy,

    Thanks for reaching out and sorry to hear about the challenge you’re facing.

    Looking at the error you shared in the error log – 535 5.7.139 Authentication unsuccessful, SmtpClientAuthentication is disabled for the Tenant.

    This message is coming directly from Microsoft. They’ve recently disabled Basic authentication for SMTP connections across Office 365 tenants. Because of this change, connecting with the “Other SMTP” mailer in WP Mail SMTP will no longer work, even if your credentials are correct.

    That said. the solution would be to consider other supported transactional mailer or use the Outlook mailer option available in WP Mail SMTP Pro, which supports Modern authentication (OAuth2). This method is secure and fully supported by Microsoft. Please note that free Outlook accounts are not eligible, you’ll need a Microsoft 365 or Azure account to generate the required credentials.

    Here’s our step‑by‑step guide with screenshots:
    https://wpmailsmtp.com/docs/how-to-set-up-the-outlook-mailer-in-wp-mail-smtp/

    And here’s a video walkthrough that shows the entire setup process:
    https://www.youtube.com/watch?v=A4IClPHbg3k

    I understand this change can be frustrating, especially since it was working before. Unfortunately, it’s a Microsoft‑side update, but once you switch to the Outlook mailer with OAuth2, you should be able to send test emails successfully again.

    Hope this clears things up and gets you back on track!

Viewing 2 replies - 1 through 2 (of 2 total)

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