535: 5.7.3 Authentication unsuccessful

After going back and forth with GoDaddy I found the solution in a mix of Microsoft Articles.  Here's the easiest way to enable the accounts:

**Open Powershell AS ADMINISTRATOR and enter the following commands:**Set-ExecutionPolicy RemoteSigned

winrm quickconfig

winrm get winrm/config/client/auth

At this point you should see something that says "Basic = true"

$UserCredential = Get-Credential

A popup box should appear, enter an administrators username and password for Exchange (e.g. emailaddress password)

$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $UserCredential -Authentication Basic -AllowRedirection

Import-PSSession $Session -DisableNameChecking

get-CASMailbox -Identity USEREMAILADDRESS | fl SmtpClientAuthenticationDisabled

Set-CASMailbox -Identity USEREMAILADDRESS -SmtpClientAuthenticationDisabled $false

Remove-PSSession $Session

My original post was cut off so I re-edited. 

This worked for me! We have a Lexmark MFP that wouldn't scan to e-mail despite the settings being 100% correct. When I ran the "get" command it already shoed "False" but I figured I'd run it anyway and now we're scanning. I don't understand why this made the difference but I wanted to let you know!

Hi 

I am facing similar unsuccessful authentication issue, I did setup complete my domain DNS settings, enable DKIM, add Dmarc, MX and etc on domain provider, also verified the domain settings populated on office365.

For the test I am using "https://www.gmass.co/smtp-test# " provide my credentials "******@ultimatecookingcourse.com", select TLS when available, smtp.office365.com, 587, but the getting this error.

Connected to smtp://smtp.office365.com:587/?starttls=when-available<< 220 MWHPR10CA0009.outlook.office365.com Microsoft ESMTP MAIL Service ready at Sat, 14 Nov 2020 00:41:07 퍍>> EHLO [172.31.10.74]<< 250-MWHPR10CA0009.outlook.office365.com Hello [35.161.55.56]<< 250-SIZE 157286400<< 250-PIPELINING<< 250-DSN<< 250-ENHANCEDSTATUSCODES<< 250-STARTTLS<< 250-8BITMIME<< 250-BINARYMIME<< 250-CHUNKING<< 250 SMTPUTF8>> STARTTLS<< 220 2.0.0 SMTP server ready>> EHLO [172.31.10.74]<< 250-MWHPR10CA0009.outlook.office365.com Hello [35.161.55.56]<< 250-SIZE 157286400<< 250-PIPELINING<< 250-DSN<< 250-ENHANCEDSTATUSCODES<< 250-AUTH LOGIN XOAUTH2<< 250-8BITMIME<< 250-BINARYMIME<< 250-CHUNKING<< 250 SMTPUTF8>> AUTH LOGIN<< 334 VXNlcm5hbWU6>> YmVuYXppcm5vb3JAdWx0aW1hdGVjb29raW5nY291cnNlLmNvbQ==<< 334 UGFzc3dvcmQ6>> dXJvb2oxMjNAPw==<< 535 5.7.3 Authentication unsuccessful [MWHPR10CA0009.namprd10.prod.outlook.com]ERROR: 535: 5.7.3 Authentication unsuccessful [MWHPR10CA0009.namprd10.prod.outlook.com]

I can able to login on office 365 into my account and can able to send emails from outlook, but it is falling with https://www.gmass.co/smtp-test#. I appreciate if the Microsoft support team can check my account and exchange settings and fix this issue, appreciate if they can resolve this issue.

Many thanks for your instructions unfortunately i ran into a hickup

I tried the same solution but I end up with:

PS C:\WINDOWS\system32> Set-CASMailbox -Identity <******@domain.com> -SmtpClientAuthenticationDisabled  $false 

A parameter cannot be found that matches parameter name 'SmtpClientAuthenticationDisabled'. 

• CategoryInfo          : InvalidArgument: (:) [Set-CASMailbox], ParameterBindingException
• FullyQualifiedErrorId : NamedParameterNotFound,Set-CASMailbox
• PSComputerName        : outlook.office365.com  

Any idea what the problem would be?

Many thanks in advance.

Kr,

Tommy

I'm not positive, but I think it may mean that the account you've entered the credentials for doesn't have full administrator permissions to change the setting.   You can always authenticate as the main admin account and then change other users.

I think it may mean that the account you've entered the credentials for doesn't have full administrator permissions to change the setting. 

I encountered those PowerShell errors and you are quite correct. I realized after reading this that I'd been authenticating using the account whose properties I was checking, instead of as an Exchange administrator.