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SMTP Auth Failure

  • Hi


    One of our users has his GMAIL setup to send as his 365 company email address


    I have checked his SMTP settings, sometimes these work fine....other times he gets the following error:-


    Technical details of permanent failure:
    Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 535 535 5.7.3 Authentication unsuccessful (SMTP AUTH failed with the remote server) (state 7).


    Any ideas?

  • Hi Mac_365,

    Are you meaning to send emails from Gmail with an Office 365 email address? If so, please check and confirm the following things are correct:

    • The Office 365 email address is a  user who has an license enabled Exchange Online mailbox
    • The SMTP set to port 587
    • Transport Layer Security (TLS) encryption enabled
    • The mailbox server name is correct

    You can find the server name information by following these steps:

    1.  Sign in to Outlook Web App.
    2.  Click Options, and then click See All Options.
    3.  Click Account, click My Account, and then in the Account Information area, click Settings for POP, IMAP, and SMTP access.

    Thanks,
    Reken Liu

  • Hi Mac_365,

    How are things going? Do you have any updates about the issue?

    Thanks,
    Reken Liu

  • The user has checked the settings and they are all fine.  It only happens once every so often...like every 10 emails.

  • Hi Mac_365,

    Based on my experience, the issue might be caused by the SMTP settings timeout value, and it should be able to fixed by enlarging the value.

    Thanks,
    Reken Liu