cPanel 11.52 update and SMTP Authentication Issue

cPanel UpdateSMTP Authentication – Possible SMTP Authentication issue due after cPanel update
Status: Workaround provided for VPS and Dedicated server
Who is affected?Email accounts on hosted sites that have been updated to cPanel 11.52

InMotion servers use a current configuration to allow SMTP authentication if the user has already authenticated via POP in the last 30 minutes. This option is unfortunately automatically disabled in version 11.52. If SMTP authentication is not properly configured in mail clients, then there may be issues with sending mail. There are a few recommended ways to fix the issue:

  1. Force SMTP authentication in the customer’s mail client. The default SMTP setting may not always be the best way to configure email clients to send mail. This may be of more importance in applications such as ecommerce where there is a choice in how to send email notifications. In these cases, make sure to use SMTP authentication for sending mail.
  2. VPS or Dedicated customers can change the settings in WHM by doing the following:

    Go to WHM > Tweak Settings
    Enable this setting: Allow users to relay mail if they use an IP address through which someone has validated an IMAP or POP3 login within the last our.

The Systems team is evaluating the update and will make changes if necessary. For more information about the cPanel update, please see cPanel 11.52 Release Notes.

Arnel Custodio Content Writer I

As a writer for InMotion Hosting, Arnel has always aimed to share helpful information and provide knowledge that will help solve problems and aid in achieving goals. He's also been active with WordPress local community groups and events since 2004.

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0 thoughts on “cPanel 11.52 update and SMTP Authentication Issue

  1. The given info about SMTP authentication issue is very helpful for me, because I am facing same issue. Hope it will help me while resolving the issue. Thanks for sharing.

  2. Hello,

    The workaround instructions above are not clear. Please post more detailed instructions on how to apply a fix to this issue. How exactly do we “force SMTP authentication”?

  3. hello TJ,


    now I can see the comments, thanks! probably they were not approved yet, cause I’ve received a notification about my first comment as if it was published just now, and everything is now visible here in the page. 😉


    anyway, I use this wordpress plugin to automatically send notifications for new posts:

    I will now try to install the plugin you are suggesting and hopefully it will work fine along with my notification plugin




  4. ok thanks for the info!

    the only problem is that I haven’t understood what I am actually supposed to do in order to apply the above workarounds to my situation.. could you please point me in the right direction?


    p.s. I don’t know why, but I can’t see any comment here on the site.. I read you reply from my email, but here within the page I don’t see any comment..

    1. Hello Andrea,

      That is a bit weird as I can see comments on incognito mode without being logged in. You can not see your comment at first as we have to approve all comments. However if you are using WordPress then you can just use the WP Mail SMTP plugin.

      Best Regards,
      TJ Edens

  5. Hello!

    I use a plugin to automatically send email notifications to my members when we publish a post. it worked perfectly till monday, and since yesterday is not sending any email..

    might this be realted to the same issue? any suggestion about it?



    1. Hello Andrea,

      This most likely is the same issue. In the post above displays two solutions to help alleviate the problem but we are still working with cPanel to resolve the issue from their end as it is a bug with their software.

      Best Regards,
      TJ Edens

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