SMTP Email Error 504 5.7.4 – How to Resolve [SOLVED]

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    Simple Mail Transfer Protocol (SMTP) is the foundation for all email communication. It dictates the framework for sending and receiving messages worldwide on various networks. Additionally, SMTP supports messaging for both personal and professional communications, basically handling the majority of daily information exchanges.

    However, the errors in SMTP, including Email Error 504 5.7.4, significantly disrupts this flow. These errors prevent real-time communication. Since it’s important to have smooth communications, it is crucial to identify and correct these errors as soon as possible.

    What is SMTP Email Error 504 5.7.4?

    SMTP Email Error 504 5.7.4 denotes issues with the authentication process during email delivery. When you come across this error, it means authentication processes are either improperly configured or unsupported—which prevents the SMTP server from processing an email.

    Those who experience this error will see notifications that specifically mention issues with authentication. Typical error messages include the following:

    • “504 5.7.4 Unrecognized authentication type” indicates that the email client’s attempted authentication mechanism is not supported or recognized by the SMTP server.
    • “504 5.7.4 Authentication mechanism is too weak” may arise when the server demands a more secure authentication method than what is currently being used.
    • “504 5.7.4 Command parameter not implemented” may sometimes be associated with authentication command parameters that the server is unable to process.

    So why does SMTP Email Error 504 5.7.4 occur?

    There are many possible reasons and scenarios why this particular error occurs, and we’re going to discuss each one.  

    1. Authentication failures

    Unsupported authentication method

    It is unlikely that the client is using an authentication mechanism that isn’t supported by the server. Instead, a more plausible explanation is that there is a mismatch in security settings somewhere. You might have tried to use a very modern and secure method of authentication that the server doesn’t recognize yet or wasn’t set up to deal with.

    Incorrect authentication settings

    If the authentication settings on the server or client’s side are misconfigured, this error might occur. This isn’t just about typing the wrong username and password. It may involve incorrect setup of security tokens, key files, or other authentication credentials.

    2. Configuration errors

    Server configuration issues

    Another possible reason behind the error is the email server might be misconfigured. This prevents it from recognizing or allowing the authentication method requested by the client. This can also include incorrect SMTP settings or authentication methods that should be enabled or disabled.

    Client configuration

    The client may be set to use an authentication method that the server doesn’t support or isn’t configured to handle. If the client’s security settings don’t match the server’s requirements, authentication failures can occur.

    Protocol mismatches

    There might be protocol mismatches between the types of SMTP or any other supporting protocol the client and server used. This could lead to misunderstandings regarding the type of authentication wanted.

    3. Server limitations

    Outdated server software

    When more advanced clients try to connect using settings that the server is unable to handle, they may see this error because the server software is out of date and does not support the more recent authentication methods.

    Restrictive server policies

    Using specific authentication techniques may also be prohibited by the stringent security standards of some servers. Certain servers, for instance, might only accept encrypted passwords and reject requests that try to use a less secure technique.

    Step-by-step guide to handle SMTP Email Error 504 5.7.4

    Gmail

    • Log in to your Gmail account.
    • Select “See all settings” from the gear icon.
    • Go to Accounts and Import. 
    • From the ‘Accounts and Import’ menu, select the ‘Send mail as’ column. Then click ‘Add another email address.’
    • Enter your name and the email address you want to send from in the popup box. If you would like to administer this account using your primary Gmail account, make sure that ‘Treat as an alias’ is ticked.
    • Under SMTP settings, do the following:
      • SMTP Server: Enter smtp.gmail.com.
      • Username: Your full Gmail address (including @gmail.com).
      • Password: Your Gmail password. If your 2-Step Verification is enabled, you will need to generate an app-specific password.
      • Port: Use 465 for SSL or 587 for TLS.
    • Verify that “Secured connection using TLS” or “Secured connection using SSL” is selected for authentication.
    • Conserve modifications. Select ‘Add Account’ and adhere to the instructions to verify the email address via a verification email.

    Outlook

    • Access the Account Settings. Navigate to File > Account Settings > Manage Profiles after opening Outlook.
    • Select “Email Accounts” from the Mail Setup box.
    • Change account. Click “Change” after selecting your email account. Check the Outgoing Mail Server (SMTP) under “Server Information.” It should be configured in accordance with your email provider (for example, smtp-mail.outlook.com for Outlook).
    • Next, go to additional settings. Select the “Outgoing Server” tab by clicking on “More Settings.” Check the box next to “My outgoing server (SMTP) requires authentication.”
    • Select the ‘Advanced’ tab. Use port 587 for SMTP then choose “TLS” for the kind of encrypted connection.
    • After selecting “Next” to allow Outlook to test your settings, click “OK” to close the More Settings window.
    • Click “Finish” and restart Outlook when the test has been successful.

    Yahoo!

    • Visit Yahoo! Mail, log in, and proceed to your account details. 
    • Click on “Account Security.”
    • Create app password. If two-factor authentication is enabled, you might need to create an app-specific password to utilize it in your email client rather than your main password.
    • Configure email client by doing the following:
      • SMTP Server: smtp.mail.yahoo.com.
      • Port: Use 465 with SSL or 587 with TLS.
      • Username: Your full Yahoo email address.
      • Password: The app password you generated, or your regular password if you don’t have two-factor authentication enabled.
    • Save settings. Ensure your email client uses these settings and re-test sending an email.

    For other clients

    • Verify SMTP settings. To determine the proper SMTP settings, including server address, port, and whether SSL/TLS is required, consult the documentation for your particular email platform.
    • Verify authentication. Make sure the email client is set up for authentication and that the username and password you are using are accurate.
    • Update or reinstall. Updating the email client to the most recent version or reinstalling it may help fix configuration issues if problems continue.
    • Contact support. To make sure your settings are accurate and accepted by the server, contact the support staff of your email provider if the error persists.

    Tackling SMTP Email Errors and email warmup go hand-in-hand

    warmy dashboard

    To eliminate the SMTP 504 5.7.4, one should closely delve into the email authentication methods’ peculiarities and make sure that both the email server and client are configured correctly to get access to supported protocols. Whether you deal with your emails through Gmail, Outlook, or Yahoo!, or through various less-known platforms, you must still align SMTP settings with server capacities and security standards.

    It’s easy to think that once you’ve completed the steps discussed above that you’re already in the clear. However, we challenge you to take the next step—one that is designed to change your email marketing game.

    Email warmup services like Warmy.io can enhance your email sending practices by slowly increasing the number of emails sent from any new or underused email account. This will help you avoid SMTP errors and keep a good sender reputation. You see, avoiding or preventing SMTP errors is one thing. But enhancing your email deliverability as a whole will lead you to long-term success.

    Properly warmed-up accounts are unlikely to be flagged by email service providers for suspicious activity, which can cause such SMTP errors. Warmy.io lets you not only do the warming process but also provides other tools that help with email deliverability. It offers free email deliverability tests that allow you to test your emails and see if everything is working fine before you start any campaign to avoid any related issues.

    Plus, the service also runs blacklist checks to make sure your email has not been flagged by any anti-spam databases. Last but not least, it provides a fancy tool to generate SPF and DMARC records. These records are needed for email authentication and email protection as they allow controlling the email that claims to be sent from your domain. 

    All these features make Warmy.io an all-in tool for managing email and ensuring it reaches your recipient. There’s a free 7-day trial you can explore—and trust us, you’ll want to make the most of it once you see what’s inside. 

    📜 Related articles:

    FAQ

    1. What does the error “504 5.7.4 unrecognized authentication type” mean?

    The authentication method being used is not recognized by the SMTP server due to configuration issues in email settings.

    2. How can I fix the “SMTP unrecognized authentication type” error?

    Check your email client’s SMTP settings. Ensure that the correct authentication method (like STARTTLS or SSL) is selected and matches the server’s requirements.

    3. Why do I see “SMTP 504” errors when trying to send emails?

    This happens when the mail server encounters an issue like unsupported authentication methods. This is a general response, often followed by “5.7.4 unrecognized authentication type,” to indicate the specific problem.

    4. What should I do if I receive a “5.7.4 unrecognized authentication type” error?

    If you encounter “5.7.4 unrecognized authentication type,” review your email client settings. Confirm that you’re using the correct SMTP protocol and authentication type. Sometimes, updating the authentication method to align with the mail server’s preferences can resolve the issue.

    5. Why does SMTP protocol error 504 5.7.4 happen?

    Sometimes, the mail server doesn’t support the specified authentication method. Maybe the email client uses outdated or unsupported settings. You should make sure that your SMTP settings match those provided by your email service.

    6. Is “504 5.7.4” a common error?

    Yes, it’s a common error in the email world, especially when there’s a mismatch in the authentication type between the email client and the SMTP server. Double-checking and updating your SMTP settings should help resolve this issue.

    7. How does the “504 5.7.4 unrecognized authentication type” error impact email delivery?

    This means your email won’t be sent until the issue is fixed. This error blocks the delivery process, as the server can’t authenticate the connection.

    8. What are some best practices for avoiding SMTP 504 errors?

    To avoid SMTP 504 errors, ensure that your email client’s SMTP settings are always up-to-date. Regularly check that the authentication type you’re using is compatible with the server, especially if you encounter “SMTP protocol error 504 5.7.4.”

    Picture of Daniel Shnaider

    Article by

    Daniel Shnaider

    Picture of Daniel Shnaider

    Article by

    Daniel Shnaider

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