diff --git a/install.sh b/install.sh
index 0daa494..c959c74 100755
--- a/install.sh
+++ b/install.sh
@@ -126,6 +126,7 @@ touch /etc/exim4/srsd.secret
 chmod 640 /etc/exim4/srsd.secret
 chown Debian-exim:Debian-exim /etc/exim4/srsd.secret
 pwgen -N 1 -cny 64 > /etc/exim4/srsd.secret
+sed -i "s|^QUEUEINTERVAL.*|QUEUEINTERVAL='15m'|g" /etc/default/exim4
 
 # dovecot config
 mkdir /etc/dovecot/sites.d