535: 5.7.3 Authentication unsuccessful

Anonymous
2020-04-16T10:47:36+00:00

Hello,

I have an issue when using an O365 account and sending emails from an application.

The application has been suitable to use tls/starttls, port 587, ect.

When entering an email account and password, the following message occurs:

"535: 5.7.3 Authentication unsuccessful"

I would like to understand, what are the mininal features of an O365 account so that it can be used from another application.

I have performed different tests, which allow me to indicate that the account is Ok.

Thank you.

Microsoft 365 and Office | Subscription, account, billing | For home | Windows

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  1. Anonymous
    2020-05-29T15:10:48+00:00

    Hi All,

    please check your MX entry.  It should be like domainname**.mail.protection.outlook.com**

    This means as SMTP server use domainname**.mail.protection.outlook.com**with port 25.

    I hope this helps.

    Best regards

    Chris

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  2. Anonymous
    2020-05-25T14:02:03+00:00

    the same problem here. hope there will be a fix!

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  3. Anonymous
    2020-05-14T17:25:20+00:00

    We have the same issue.  Mails sending fine until March then suddenly stopped from April.

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  4. Anonymous
    2020-05-08T22:20:22+00:00

    Hi Marvin,

    We have same issue. The application was sending email till march. The issue started happening from April 2020 it self. 

    Please help as soon as possible.

    Thanks

    Hello,

    We have the same issue here as well.

    Not sure how to fix it... is there any issues from Microsofts end?

    I have another account which is working - however just got a new account today and it's having the same issues as the above mentioned.

    Did you find any solution?

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  5. Anonymous
    2020-05-05T13:18:42+00:00

    Hi Marvin,

    We have same issue. The application was sending email till march. The issue started happening from April 2020 it self. 

    Please help as soon as possible.

    Thanks

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