Inotify initialization error in Plesk | An Easy Fix

Inotify initialization error in Plesk is no longer a problem with Bobcares by your side. 

At Bobcares, we offer solutions for every query, big and small, as a part of our Server Management Service.

Let’s take a look at how our Support Team is ready to help customers with the Inotify initialization error in Plesk.

How to resolve Inotify initialization error in Plesk

The inotfiy initialization error prevents the Plesk server from sending out emails via an email client like Outlook. It results in the following error message:

Your IMAP server wants to alert you to the following: Inotify initialization error

Furthermore, the courier IMAP server is put to use for IMAP/POP3 delivery. Our Support Engineers also recommend checking the /var/log/maillog log file for the following error messages:

plesk courier-imaps: Failed to create cache file: maildirwatch (
plesk courier-imaps: Error: Too many open files
Inotify initialization error in Plesk

Interestingly, this specific error is due to an inadequate per-userid limit value of the inotify file descriptors. Fortunately, our Support Techs put their heads together to come up with this easy resolution:

  1. First, we will connect to the server through SSH.
  2. Then, we have to take a look at the current value of the per-userid limit of the inotify file descriptors with the following command:
    # cat /proc/sys/fs/inotify/max_user_instances
  3. Next, we will increase the current value to a greater one with the help of the command below:
    # echo "fs.inotify.max_user_instances=300" >> /etc/sysctl.conf

    For instance, here we are increasing the value from 228 to 300. Our Support Engineers recommend increasing the value to a number roughly four times the number of concurrent IMAP sessions.

  4. After that, we will apply the changes made with this command:
    # sysctl -p
  5. Finally, we will restart the Courier-Imap services for the changes to take effect:
    # systemctl restart courier*

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To conclude, our skilled Support Engineers at Bobcares demonstrated how to deal with the Inotify initialization error in Plesk.


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