Corrective Actions For SMTP Error 535 Authentication Error

Hopefully, if authentication fails on your system due to SMTP error 535, this guide can help you.

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    SMTP Error 530 Authentication Required is an error that a worker receives when sending email messages. This error occurs when users configure invalid go data, blacklist the sender’s IP address, etc. At Bobcares, as part of our server administration services, we receive frequent requests to fix SMTP errors.


    Everyone sends emails to reach their goal without issue, but it usually doesn’t work.
    smtp error 535 authentication failed


    Mail servers may reject emails with strange errors, for example, via “SMTP error (535): authentication failed”

    At Bobcares, as part of our technical support services, we frequently receive requests from customers to troubleshoot SMTP errors.

    Today, we’ll take a look at how our technical support team helps our customers fix such serious email errors.

    What Is SMTP Authentication?

    How do I fix SMTP Error 535?

    Open Thunderbird by going toGo to Tools -> Account Settings -> Outgoing Mail Server (SMTP), usually select Outgoing Mail Server by clicking the item, then click the Change button. In the Security and Authentication section, select the Username and Password check box. Enter the username for your email account and click OK.

    smtp error 535 authentication failed

    Email applications such as Outlook use SMTP mail to send messages. To download one of our email clients later, please use POP or IMAP.

    How do I fix SMTP authentication error?

    Open the process of your mail client (Outlook Express, Outlook, Eudora or Windows Mail)On the Tools menu, click Accounts.Go to your email account and click the Properties button.Click the General tab.Please make sure our “Email Address” is your valid personal address for this account.Click the Server tab.

    But for many reasonsa client like Outlook throws the correct error message if the authentication email doesn’t work.

    The error “SMTP Error (535): Authentication Failed” is usually associated with incorrect user email settings in Microsoft Outlook.

    For this reason, customer customization always requires special attention. Now let’s take a look at the causes of these errors and how our support engineers fix them for customers.

    Reasons For “Error 535: Authentication Failed”

    In our experience with managing servers and scavenging systems, we often find that clients have authentication error 535 for the following reasons:

    1. Incorrect Username And Then Password

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  • If the username and account information in the mail client is generally incorrect, you will see error 535. Again, using the entire mail server can lead to errors. authorization.

    Typically, mismatches between usernames and passwords in e-mail messages are recorded in the mail server logs. It helps a lot Find an accurate webmail account if something goes wrong.

    2. Account Deactivated

    Likewise, the story can sometimes be turned off due to billing fees or spam. This also results in SMTP error (535): Authentication failed.

    So it’s very interesting to enter the bar at the top and check the status in both the customer account and the email account.

    3. SMTP Authentication

    If SMTP authentication for your mail client is not enabled, this may also result in an error. Now let’s see how SMTP authentication is enabled on the server side and on the client side of the internet hosting.

    How It Helps To Set Up SMTP Authentication In A Good Email Client

    If SMTP authentication is disabled on the client, e-mail error messages will appear as follows: “Server reporting: SMTP error (535): Authentication failed: Authentication failed.”

    Fortunately, setting up SMTP authentication is a straightforward process. This includes changing the SMTP configuration settings and making any necessary changes y.

    1. Open Thunderbird, go to Tools -> Account Settings -> Outgoing Mail Server
    2. Select (smtp)
    3. to this outbound server by clicking the issue and then clicking the Edit button.

    4. In the Security and Authentication section, enable the Username and Password option.
    5. Fill in this field with your email account username and click OK.

    Enable SMTP Authentication On Server

    Why does SMTP authentication fail?

    Certain conditions can cause authentication to fail: Invalid username. This will usually be the same as your email address, but some SMTP servers require a different set of credentials than the one you use to receive emails. The username and password are incorrect.

    We have just seen how to enable SMTP authentication in an email client. However, for this to work, the server must support SMTP authentication. Let’s see how dedicated our engineers are to make this guide available to our customers.

    SMTP Authentication on Plesk Server

    SMTP connections to the Plesk server usually need to be checked. Recently, one of our clients asked us to fix “SMTP Our Own Error (535): Authentication Failed”. Here the computer has not set Auth-SMTP to ON. Therefore, our support engineers solved each of our problems by enabling “SMTP Authentication” between their serversamy Plesk.

    1. We are signed in to Plesk.
    2. We monitored the SMTP authorization status under Tools & Settings> Server Mail Settings> Relay Settings.
    3. Finally, we have created the correct settings in & Tools Settings> Mail Server Settings> Enable SMTP service on port 587 for all IP addresses.

    Enable SMTP in cPanel Authentication

    Let’s see how to initiate SMTP authentication on the cPanel server. SMTP Authentication cPanel allows you to send messages using POP-before-SMTP. After Outlook downloads your mail, you don’t need to re-authenticate to send mail using SMTP.

    Usually, SMTP authentication is disabled by default in WHM. To enable SMTP authentication we go to WHM >> Service Configuration >> Service Manager, so check the Antirelayd checkbox.


    [Having trouble with SMTP authentication? We can fix it for you.]


    In short, the “SMTP Error (535): Authentication Failed” error occurs when there is a practical problem with the SMTP configuration of email clients. С Last year we saw Bobcares fix “SMTP Authentication Error 535”.


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    Ошибка SMTP 535 Ошибка аутентификации
    Erro Smtp 535 Autenticação Falhou
    Błąd SMTP 535 Uwierzytelnianie Nie Powiodło Się
    Erreur SMTP 535 Échec De L’authentification
    SMTP 오류 535 인증 실패
    SMTP-Fehler 535 Authentifizierung Fehlgeschlagen
    Error SMTP 535 Autenticación Fallida
    Errore SMTP 535 Autenticazione Non Riuscita
    Smtp-fout 535 Verificatie Mislukt