Invalid login: 535 5.7.3 Authentication unsuccessful in MS 365 mail

I have tried to Send Email to MS 365 Email But its throws error like “Invalid login: 535 5.7.3 Authentication unsuccessful”. Same way I have tried other tools like Zapier, Zoho, its working perfectly and got the Email.

Note that Email 365 connection created and saved the connection page, in that page also I just reauth and verify, its got successfull, Only issue is here, when send the mail got the above mentioned error.

Note that In My Email I have enabled all SMTP related configuration.

Hi @isquareinfo, I got a workaround for it and it’s successful in sending the email.

Select ‘Other’ from the Create a Connection dropdown and select ‘Other’ in the email provider as well. In the ‘SMTP Server Name’ type in your server address. If you’re using SMTP then the address should be ‘’.

Port should be ‘587’.

Secure connection should ‘Yes’

Use explicit TLS should also be ‘Yes’.

Enter you’re user credentials and you’ll be good to go.

You can find reference to the above here.
Let me know how you get on. Cheers.

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