diff --git a/roles/mail_server/tasks/main.yml b/roles/mail_server/tasks/main.yml
index 9a0529c2a8c057a26bce0aaed2736fbae5395b1d..cb61b241c13158d134d20e39896afb280129503c 100644
--- a/roles/mail_server/tasks/main.yml
+++ b/roles/mail_server/tasks/main.yml
@@ -89,6 +89,16 @@
   notify:
     - Restart Dovecot
 
+- name: Generate the IMAP server Diffie-Hellman parameter
+  openssl_dhparam:
+    owner: root
+    group: root
+    mode: 0640
+    path: "/etc/ssl/private/{{ ansible_fqdn }}_imap.dh.pem"
+    size: 2048
+  notify:
+    - Restart Dovecot
+
 - name: Deploy configuration files for checking certificate validity via cron
   copy:
     content: "/etc/ssl/certs/{{ ansible_fqdn }}_{{ item }}.pem"