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
    2020-06-01T12:04:06+00:00

    HI Chris,

    We have this MX entry for our domain apicalsolutions.com

    apicalsolutions.com. MX (10) apicalsolutions-com.mail.protection.outlook.com.

    Is this correct? If yes then it is still not working. 

    Best Regards

    Vishwas

    Hi Vishwas,

    so you should use as SMTP server: apicalsolutions-com.mail.protection.outlook.com with port 25.

    As user use any user of your domain. Even if it has no linked mailbx you can use it for login.

    Usually it should work.

    https://docs.microsoft.com/de-de/exchange/mail-flow-best-practices/how-to-set-up-a-multifunction-device-or-application-to-send-email-using-office-3#settings-for-direct-send

    Do you get any error message?

    Best regards

    Chris

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  2. 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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  3. Anonymous
    2020-07-13T17:18:06+00:00

    I had a similar issue. The problem is that Microsoft doesn't automatically turn on SMTP servers anymore.  Talk to your mail hosting company (in my case, it's GoDaddy) and they'll turn them on. Took 3 tech support guys at GoDaddy to finally figure this out.

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

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

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  5. 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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