# [SMTPD_PID_FILE_LOCK](https://apps.juniper.net/syslog-explorer/?msg=SMTPD_PID_FILE_LOCK)

## SYSLOG Details
- **Message**: Unable to lock PID file:<variable>error-message</variable>
- **Help**: SMTP client daemon could not lock PID file
- **Description**: The smtp client process (smtpd) attempted to lock the file that records its process ID (PID), which serves to prevent multiple instances of smtpd from running simultaneously. It could not lock the file and exited after logging this message.
- **Type**: SNO: Should Not Occur
- **Severity**: error
- **Cause**: -
- **Action**: -
- **Attributes**: error-message
- **Facility**: LOG_DAEMON

## Found this message in the following releases:
- [Junos OS 24.2R1](https://apps.juniper.net/syslog-explorer/?msg=SMTPD_PID_FILE_LOCK&sw=Junos%20OS&rel=24.2R1)
- [Junos OS 23.4R1](https://apps.juniper.net/syslog-explorer/?msg=SMTPD_PID_FILE_LOCK&sw=Junos%20OS&rel=23.4R1)