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Microsoft 365 SMTP Authentication Set up Issues

Hi there,

 

I'm using external apps to send mail through SMTP. I have build a php script to send emails from my account unfortunately my Office 365 email account does not. Although, worked fine when using google smtp but not my business Office 365 smtp. The failure is simply an authentication error in SMTP and I'm sure the credentials are correct, as I haven't found anything online about that.

 

Any help is greatly appreciated

Eli

Answer
Answer

Hi Eli,

Thank you for posting. Please make sure that you entered the correct username and password. Try logging into Outlook on the web with the username and password. Send an email to make sure that the mailbox is active and has not been blocked for sending spam. You may also check that your application supports TLS version 1.2 or above.

Moreover, if you receive one of the following errors 535 5.7.3 Authentication unsuccessful/5.7.57 Client not authenticated to send mail. There are a few things you need to check, see under Error: Authentication unsuccessful.

If anything unclear, please feel free to let us know. We will be glad to help you.

Best regards,

Shyamal

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Question Info

Last updated July 2, 2022 Views 838 Applies to: