Messages about process limit overuse are logged in maillog on the Plesk server

Kuzma Ivanov

Updated January 07, 2025 06:40

Plesk for Linux

Applicable to:

Messages about process limit overuse for Postfix and Dovecot services are logged in /var/log/maillog:

CONFIG_TEXT: postfix/master[6397]: warning: service "smtp" (25) has reached its process limit "10": new clients may experience noticeable delays

CONFIG_TEXT: dovecot: master: Warning: service(imap-login): process_limit (100) reached, client connections are being dropped
As the result the the following types of unexpected EOF is registered in /var/log/maillog:

CONFIG_TEXT: postfix/smtpd[15038]: warning: read TCP map reply from 127.0.0.1:12346: unexpected EOF (Connection reset by peer)
postfix/smtpd[30250]: warning: read TCP map reply from 127.0.0.1:12346: unexpected EOF (Connection timed out)

Process limit was reached for Postfix/Dovecot service.

Increase the process limit: for Postfix/Dovecot services by using the solutions below:

For smtp (Postfix)

Connect to your Plesk server via SSH.
Open the file /etc/postfix/main.cf in a text editor. In this example, we are using the vi editor:

# vi /etc/postfix/main.cf
Add the line below at the end of the file:

CONFIG_TEXT: default_process_limit = 50
Save the changes and close the file.
Restart Postfix service to apply the changes:

# service postfix restart

For imap-login (Dovecot)

Connect to your Plesk server via SSH.
Open the file /etc/dovecot/conf.d/92-plesk-service-imap-login.conf in a text editor. In this example, we are using the vi editor:

# vi /etc/dovecot/conf.d/92-plesk-service-imap-login.conf
Locate the line with process_limit directive and increase its value.
Save the changes and close the file.
Restart the Dovecot service to apply the changes:

# service dovecot restart