Requirements

Before you start, you will need:

• Root access enabled
• Connect to your (dv) via SSH
• vi knowledge

Symptoms

I am trying to send a message from Webmail but the following error appears:

Failed to open sendmail [/var/qmail/bin/sendmail] for execution.

The same error is also seen in the log file located at /var/log/psa-horde/psa-horde.log.

Solution

There can be two reasons for this problem. Please check them:
- Make sure that *exec* or *open* functions are not disabled, i.e. not in listed in "disable_functions" directive in php.ini files. You can search for this using the grep command:

# grep -i disable_functions /etc/php.ini /etc/php.d/* /usr/local/etc/php.ini 

To make sure that "disable_functions" do not affect webmail, you can comment out this line by putting a '#' symbol at the beginning of this line. Then restart Apache and try to send an email again. If this works, try disabling functions one by one, restarting Apache and checking mail sending through webmail each time.