diff --git a/roles/mail_server/tasks/main.yml b/roles/mail_server/tasks/main.yml
index ab91828469b1a2a68b8fe4104dbd1d39d74e07f2..4024e27bc0efe4ff088893d6b5731906293ddc28 100644
--- a/roles/mail_server/tasks/main.yml
+++ b/roles/mail_server/tasks/main.yml
@@ -43,7 +43,7 @@
   copy:
     dest: "/etc/ssl/private/{{ ansible_fqdn }}_smtp.key"
     content: "{{ smtp_tls_key }}"
-    mode: 0640
+    mode: "0640"
     owner: root
     group: root
   notify:
@@ -53,7 +53,7 @@
   copy:
     dest: "/etc/ssl/certs/{{ ansible_fqdn }}_smtp.pem"
     content: "{{ smtp_tls_certificate }}"
-    mode: 0644
+    mode: "0644"
     owner: root
     group: root
   notify:
@@ -63,7 +63,7 @@
   openssl_dhparam:
     owner: root
     group: root
-    mode: 0640
+    mode: "0640"
     path: "/etc/ssl/private/{{ ansible_fqdn }}_smtp.dh.pem"
     size: 2048
   notify:
@@ -73,7 +73,7 @@
   copy:
     dest: "/etc/ssl/private/{{ ansible_fqdn }}_imap.key"
     content: "{{ imap_tls_key }}"
-    mode: 0640
+    mode: "0640"
     owner: root
     group: root
   notify:
@@ -83,7 +83,7 @@
   copy:
     dest: "/etc/ssl/certs/{{ ansible_fqdn }}_imap.pem"
     content: "{{ imap_tls_certificate }}"
-    mode: 0644
+    mode: "0644"
     owner: root
     group: root
   notify:
@@ -93,7 +93,7 @@
   openssl_dhparam:
     owner: root
     group: root
-    mode: 0640
+    mode: "0640"
     path: "/etc/ssl/private/{{ ansible_fqdn }}_imap.dh.pem"
     size: 2048
   notify:
@@ -105,7 +105,7 @@
     dest: "/etc/check_certificate/{{ ansible_fqdn }}_{{ item }}.conf"
     owner: root
     group: root
-    mode: 0644
+    mode: "0644"
   with_items:
     - smtp
     - imap
@@ -124,7 +124,7 @@
   copy:
     dest: "/etc/clamav/clamav-milter.conf"
     src: "clamav-milter.conf"
-    mode: 0644
+    mode: "0644"
     owner: root
     group: root
   notify:
@@ -133,7 +133,7 @@
 - name: Set-up privileges for directories within Postfix chroot
   file:
     dest: "{{ item }}"
-    mode: 0755
+    mode: "0755"
     state: directory
     owner: root
     group: root
@@ -147,7 +147,7 @@
     state: directory
     owner: clamav
     group: clamav
-    mode: 0755
+    mode: "0755"
   with_items:
     - /var/spool/postfix/var/run/clamav
 
@@ -157,7 +157,7 @@
     dest: "/etc/ssl/certs/mail_ldap_tls_truststore.pem"
     owner: root
     group: root
-    mode: 0644
+    mode: "0644"
 
 - name: Deploy the LDAP TLS truststore in Postfix chroot
   copy:
@@ -165,7 +165,7 @@
     dest: "/var/spool/postfix/etc/ssl/certs/mail_ldap_tls_truststore.pem"
     owner: root
     group: root
-    mode: 0644
+    mode: "0644"
   notify:
     - Restart Postfix
 
@@ -175,7 +175,7 @@
     dest: "/etc/mailname"
     owner: root
     group: root
-    mode: 0644
+    mode: "0644"
   notify:
     - Restart Postfix
 
@@ -185,7 +185,7 @@
     dest: "/etc/postfix/{{ item }}.cf"
     owner: root
     group: postfix
-    mode: 0640
+    mode: "0640"
   with_items:
     - ldap-virtual-alias-maps
     - ldap-virtual-mailbox-domains
@@ -199,7 +199,7 @@
     dest: "/etc/postfix/main.cf"
     owner: root
     group: root
-    mode: 0644
+    mode: "0644"
   notify:
     - Restart Postfix
 
@@ -241,7 +241,7 @@
     dest: "/etc/dovecot/conf.d/99-local.conf"
     owner: root
     group: root
-    mode: 0644
+    mode: "0644"
   notify:
     - Restart Dovecot
 
@@ -251,7 +251,7 @@
     dest: "/etc/dovecot/dovecot-ldap.conf.ext"
     owner: root
     group: root
-    mode: 0600
+    mode: "0600"
   notify:
     - Restart Dovecot
 
@@ -261,7 +261,7 @@
     dest: "/etc/postfix/master.cf"
     owner: root
     group: root
-    mode: 0644
+    mode: "0644"
   notify:
     - Restart Postfix
 
@@ -320,7 +320,7 @@
     dest: "/etc/ferm/conf.d/20-mail.conf"
     owner: root
     group: root
-    mode: 0640
+    mode: "0640"
   notify:
     - Restart ferm