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On my Wordpress site I've run into a problem in the last day or so, where emails simply fail to send. Before today it was running flawlessly for two months. The account information/password/username etc have not changed in that two months.
I'm using a Wordpress plugin called WP Mail SMTP to facilitate the sending of all outgoing emails. The error log I'm getting from the email test on that is as follows:
Versions:
WordPress: 5.3.2
WordPress MS: No
PHP: 7.3.14-5+0~20200202.52+debian9~1.gbpa71879
WP Mail SMTP: 1.8.1
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 1.1.1d 10 Sep 2019
SMTP Debug:
2020-02-10 16:36:56 Connection: opening to smtp.office365.com:587, timeout=300, options=array ()
2020-02-10 16:36:56 Connection: opened
2020-02-10 16:36:56 SERVER -> CLIENT: 220 LNXP123CA0008.outlook.office365.com Microsoft ESMTP MAIL Service ready at Mon, 10 Feb 2020 16:36:55 +0000
2020-02-10 16:36:56 CLIENT -> SERVER: EHLO www.*****.com
2020-02-10 16:36:56 SERVER -> CLIENT: 250-LNXP123CA0008.outlook.office365.com Hello [***]250-SIZE 157286400250-PIPELINING250-DSN250-ENHANCEDSTATUSCODES250-STARTTLS250-8BITMIME250-BINARYMIME250-CHUNKING250 SMTPUTF8
2020-02-10 16:36:56 CLIENT -> SERVER: STARTTLS
2020-02-10 16:36:56 SERVER -> CLIENT: 220 2.0.0 SMTP server ready
2020-02-10 16:36:56 CLIENT -> SERVER: EHLO www.zestpromotional.com
2020-02-10 16:36:56 SERVER -> CLIENT: 250-LNXP123CA0008.outlook.office365.com Hello [***]250-SIZE 157286400250-PIPELINING250-DSN250-ENHANCEDSTATUSCODES250-AUTH LOGIN XOAUTH2250-8BITMIME250-BINARYMIME250-CHUNKING250 SMTPUTF8
2020-02-10 16:36:56 CLIENT -> SERVER: AUTH LOGIN
2020-02-10 16:36:56 SERVER -> CLIENT: 334 VXNlcm5hbWU6
2020-02-10 16:36:56 CLIENT -> SERVER: c2FsZXNAemVzdHByb21vdGlvbmFsLmNvbQ==
2020-02-10 16:36:56 SERVER -> CLIENT: 334 UGFzc3dvcmQ6
2020-02-10 16:36:56 CLIENT -> SERVER: QmFkMzM4MzA=
2020-02-10 16:37:02 SERVER -> CLIENT: 535 5.7.3 Authentication unsuccessful [LNXP123CA0008.GBRP123.PROD.OUTLOOK.COM]
2020-02-10 16:37:02 SMTP ERROR: Password command failed: 535 5.7.3 Authentication unsuccessful [LNXP123CA0008.GBRP123.PROD.OUTLOOK.COM]
SMTP Error: Could not authenticate.
2020-02-10 16:37:02 CLIENT -> SERVER: QUIT
2020-02-10 16:37:02 SERVER -> CLIENT: 221 2.0.0 Service closing transmission channel
2020-02-10 16:37:02 Connection: closed
SMTP Error: Could not authenticate.
Does anyone have any ideas at all? I'm completely at a loss here.
Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
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Followed instructions provided and disabled modern authentication. via MS 365 Admin center Confirmed this changed Azure as well. Contact Us email from my business website were received. Back in business, for now. Thanks all for the help.
Yes - I guess it is Microsoft's way of inducing developers to use OAuth2 instead of basic authentication! And since the latter has been deprecated for IMAP and POP for a couple of years (but was only recently 'undeprecated' again - at least temporarily) it seems fair enough I guess, although it has given lots of people, me included, a headache trying to get things working. SMTP AUTH with basic authentication was never officially deprecated but branded as 'insecure'. It's worth noting, however that Conditional Access policies are not available 'from the AAD menu' in Business Basic or Business Standard accounts, although low-level policies such as 'switch on modern authentication' or 'block basic authentication' can be defined and then be allocated to an account (rather than broad-brush tenant-wide) using 365 Powershell.
Have you tried the solution I've posted?
Having the same problem. Has anyone found a resolution to this latest SMTP authentication problem? MS Office tells me to pay my web host to fix. Web host tells me MS 365 should fix it. Anyone from Microsoft listening?
Thanks Timme B81. To run the Powershell code I had to use an admin Powershell, and in it first run Set-ExecutionPolicy RemoteSigned
In my case SmtpClientAuthenticationDisabled was already false, so I'm still stuck. There is a good list of various settings to check at https://kontext.tech/column/aspnet-core/481/send-emails-using-microsoft-365-in-aspnet-core, but they're all ok too.