Office365 - smtp authentication - failure

Are you in hybrid?

Have you tried to send an email from gmail or hotmail to your tenant?

Thanks for your answer.

Yes, we are hybrid.

The problem is, that we have a ticket-tool (third party) which has to send emails via basic authentication (smtp authentication).

Receiving mails isn´t the problem.

In addition to the suggestion provided by michev in your original thread, please also try using the command below to test the account again:

$EmailFrom = “myaccount@domain.com”  
$EmailTo = “emailaddress@domain.com”  
$Subject = “Test from O365 SMTP”  
$Body = “Test from O365 SMTP Authentication”  
$SMTPServer = “smtp.office365.com”  
$SMTPClient = New-Object Net.Mail.SmtpClient($SmtpServer, 587)  
$SMTPClient.EnableSsl = $true  
$SMTPClient.Credentials = New-Object System.Net.NetworkCredential(“myaccount@domain.com”, “*****”);  
$SMTPClient.Send($EmailFrom, $EmailTo, $Subject, $Body)  

please check the following requirements for SMTP client submission:

1. Authentication: You must be able to configure a user name and password to send email on the device.
2. Mailbox: You must have a licensed Office 365 mailbox to send email from.
3. Transport Layer Security (TLS): Your device must be able to use TLS version 1.0 and above.
4. Port: Port 587 or port 25 is required and must be unblocked on your network.

And the official document here about How to set up a multifunction device or application to send email using Microsoft 365 or Office 365

If the response is helpful, please click "Accept Answer" and upvote it.