So I check what's the permissions of /var/spool/exim/ :
drwxr-x--- 2 mail mail 4096 Mar 11 15:44 db
drwxr-x--- 2 mail mail 114688 Mar 11 15:57 input
drwxr-x--- 2 mail mail 49152 Mar 11 15:47 msglog
drwxr-x--- 2 mail mail 4096 Mar 11 15:57 scan
And then I add mail to the clamav and vscan groups
clamav:x:591:mail
vscan:x:592:mail
I did a HUP, restart daemons, and finaly a reboot, but nothig changes this
error.