Exim can't send email (unable to set gid or uid forcing real = effective)

I’ve a debian Jessie and Exim4. I can’t send email from php, error given is:
unable to set gid=33 or uid=0 (euid=0): forcing real = effective

I’ve tried to search for this problem but nothing helps me.

One solution found was to add trusted_user in exim configuration, but not works either

Someone can help me?

yum shell

remove ea-apache24-mod_mpm_prefork

remove ea-apache24-mod_cgid

install ea-apache24-mod_mpm_event

install ea-apache24-mod_cgi

run

quit