Knowledge Base

Mail form or mail forwarding does not work on Plesk server: execve(/usr/lib/plesk-9.0/sendmail/sendmail.postfix) failed: Permission denied [13]

Symptoms

Mail forwarding or mailing form on a website hosted in Plesk does not work.

The following error message can be found in /var/log/maillog:

sendmail[16679]: my_popen(): execve(/usr/lib/plesk-9.0/sendmail/sendmail.postfix) failed: Permission denied [13] sendmail[16679]: Unable to execute MTA

plesk sendmail[2118]: Unable to save stdin content to temporary file
plesk sendmail[2120]: cannot create temporary file - (13) Permission denied

The permissions for sendmail.postfix or postfix-sendmail-wrapper files are set as follows:
- on CentOS/RHEL-based distributions:
  
  # stat /usr/lib64/plesk-9.0/sendmail/sendmail.postfix
  Access: (0750/-rwxr-x—) Uid: ( 0/ root) Gid: ( 0/ root)
  
  # stat /usr/lib64/plesk-9.0/postfix-sendmail-wrapper
  Access: (4750/-rwsr-x—) Uid: ( 0/ root) Gid: ( 0/ root)
- on Debian/Ubuntu-based distributions
  
  # stat /usr/lib/plesk-9.0/sendmail/sendmail.postfix
  Access: (0750/-rwxr-x—) Uid: ( 0/ root) Gid: ( 1010/postdrop)
  
  # stat /usr/lib/plesk-9.0/postfix-sendmail-wrapper
  Access: (4750/-rwsr-x—) Uid: ( 0/ root) Gid: ( 1010/postdrop)

Cause

Incorrect permissions or ownership on the Sendmail binary files.

Resolution

Connect to the server via SSH.
Set the correct permissions:

on CentOS/RHEL-based distributions

# chown root:root /usr/lib64/plesk-9.0/sendmail/sendmail.postfix && chmod 755 /usr/lib64/plesk-9.0/sendmail/sendmail.postfix
# chown root:root /usr/lib64/plesk-9.0/postfix-sendmail-wrapper && chmod 4755 /usr/lib64/plesk-9.0/postfix-sendmail-wrapper
on Debian/Ubuntu-based distributions

# chown root:root /usr/lib/plesk-9.0/sendmail/sendmail.postfix && chmod 755 /usr/lib/plesk-9.0/sendmail/sendmail.postfix
# chown root:root /usr/lib/plesk-9.0/postfix-sendmail-wrapper && chmod 4755 /usr/lib/plesk-9.0/postfix-sendmail-wrapper