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M2 send proboem says " The server responded: 533.5.7.3 Authorization unsuccessful"

  • Hi all,

    I have not changed the SMTP nor any setting.

    M2 appears sometime not sending and popup error box say " The server responded: 533.5.7.3 Authorization unsuccessful"

    How do I fix this issue ?

    Thank you.

  • For the SMTP server, make sure you're not using port 25 (even if it worked before). Use port 587 (with TLS checked if possible) or port 465 with TLS checked.

    Retype your username and password. If your username is supposed to be your email address, make sure to include the @... part.

    Make sure the address you're sending to is correct and isn't blacklisted by the server. Try sending to another address to see if that works. Maybe the person you're trying to send to has an Inbox that's full.

    Check to make sure anti-virus isn't interfering.

    Trying with another email client to make sure it's at least working there.

  • Thanks burnout426,

    Problem is that, Opera will send it when it like to send.

    I have this in the outbox & keep nagging me the error dialogue box, I return later on to my desk & it sent during I was away.

    Don't understand why Opera behave this SMTP error.