diff --git a/README.md b/README.md
index b9d7f9b8..79a16010 100644
--- a/README.md
+++ b/README.md
@@ -27,6 +27,7 @@ Then launch `configure-module`, by setting the following parameters:
 - fully qualified domain name for Nextcloud
 - let's encrypt option
 - LDAP domain (optional)
+- use internal Nextcloud mail sending settings or the cluster smarthost
 
 Example:
 ```
@@ -35,7 +36,8 @@ api-cli run module/nextcloud1/configure-module --data - <<EOF
     "host": "nextcloud.nethserver.org",
     "lets_encrypt": true,
     "domain": "ad.nethserver.org",
-    "password": "Nethesis,1234"
+    "password": "Nethesis,1234",
+    "internal_smarthost": false
 }
 EOF
 ```
diff --git a/imageroot/actions/get-configuration/20read b/imageroot/actions/get-configuration/20read
index 09b27bf5..0f5467f5 100755
--- a/imageroot/actions/get-configuration/20read
+++ b/imageroot/actions/get-configuration/20read
@@ -79,5 +79,8 @@ config["is_collabora"] = True if array_collabora else False
 if "tls_verify_collabora" not in config:
     config["tls_verify_collabora"] = False
 
+if "internal_smarthost" not in config:
+    config["internal_smarthost"] = False
+
 # Dump the configuration to stdout
 json.dump(config, fp=sys.stdout)
diff --git a/imageroot/bin/discover-smarthost b/imageroot/bin/discover-smarthost
index 6dfff4e1..df632022 100755
--- a/imageroot/bin/discover-smarthost
+++ b/imageroot/bin/discover-smarthost
@@ -17,17 +17,17 @@ smtp_settings = agent.get_smarthost_settings(rdb)
 
 envfile = "smarthost.env"
 
+with open('config.json', 'r') as cf:
+    config = json.loads(cf.read())
+
 # Using .tmp suffix: do not overwrite the target file until the new one is
 # saved to disk:
-if not smtp_settings['host']:
+if not smtp_settings['host'] or config['internal_smarthost'] == True:
     f = open(envfile, "w")
     f.write("")
     f.close
     sys.exit(0)
 
-with open('config.json', 'r') as cf:
-    config = json.loads(cf.read())
-
 domain = config['host'].split('.',1)[1]
 
 with open(envfile + ".tmp", "w") as efp:
diff --git a/imageroot/bin/setup-smtp b/imageroot/bin/setup-smtp
index 447e1002..503137cd 100755
--- a/imageroot/bin/setup-smtp
+++ b/imageroot/bin/setup-smtp
@@ -6,6 +6,7 @@
 #
 
 import agent
+import json
 import subprocess
 
 def occ(args):
@@ -13,13 +14,36 @@ def occ(args):
     p = subprocess.run(cmd + args, capture_output=True)
     return (p.returncode, p.stdout)
 
+def occget(args):
+    cmd = ['podman', 'exec', '--user', 'www-data', 'nextcloud-app', 'php', './occ']
+    p = subprocess.run(cmd + args, capture_output=True)
+    return (p.stdout.decode()[:-1])
+
 smarthost= agent.read_envfile("smarthost.env")
+smtphost= occget(["config:system:get","mail_smtphost"])
+
+with open('config.json', 'r') as cf:
+    config = json.loads(cf.read())
+
+# Remove mail configuration when smarthost is disabled
+if 'SMTP_HOST' not in smarthost and config['internal_smarthost'] == False and smtphost:
+    occ(["config:system:delete","mail_from_address"])
+    occ(["config:system:delete","mail_smtpmode"])
+    occ(["config:system:delete","mail_sendmailmode"])
+    occ(["config:system:delete","mail_domain"])
+    occ(["config:system:delete","mail_smtphost"])
+    occ(["config:system:delete","mail_smtpauth"])
+    occ(["config:system:delete","mail_smtpport"])
+    occ(["config:system:delete","mail_smtpname"])
+    occ(["config:system:delete","mail_smtppassword"])
+    occ(["config:system:delete","mail_smtpsecure"])
+    occ(["config:system:delete","mail_smtpauthtype"])
+    occ(["config:system:delete","mail_smtpstreamoptions"])
+
 # smarthost is configured
-if 'SMTP_HOST' in smarthost:
+if 'SMTP_HOST' in smarthost and config['internal_smarthost'] == False:
     # verify if smarthost verify tls certificate
     if smarthost.get('SMTP_SECURE') == 'none' or smarthost.get('SMTP_TLS_VERIFY') == 'False':
         occ(["config:system:set","mail_smtpstreamoptions","ssl","allow_self_signed","--value=true", "--type=boolean"])
         occ(["config:system:set","mail_smtpstreamoptions","ssl","verify_peer","--value=false","--type=boolean"])
         occ(["config:system:set","mail_smtpstreamoptions","ssl","verify_peer_name","--value=false","--type=boolean"])
-    else:
-        occ(["config:system:delete","mail_smtpstreamoptions","ssl"])
diff --git a/imageroot/update-module.d/17smarthost_switch b/imageroot/update-module.d/17smarthost_switch
new file mode 100755
index 00000000..dd5bf3ee
--- /dev/null
+++ b/imageroot/update-module.d/17smarthost_switch
@@ -0,0 +1,44 @@
+#!/usr/bin/env python3
+
+#
+# Copyright (C) 2026 Nethesis S.r.l.
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+
+import agent
+import json
+import subprocess
+import sys
+
+def occget(args):
+    cmd = ['podman', 'exec', '--user', 'www-data', 'nextcloud-app', 'php', './occ']
+    p = subprocess.run(cmd + args, capture_output=True)
+    return (p.stdout.decode()[:-1])
+
+smarthost = agent.read_envfile("smarthost.env")
+
+with open('config.json', 'r') as cf:
+    config = json.loads(cf.read())
+
+# Exit if internal smarthost is already set
+if "internal_smarthost" in config:
+    sys.exit(0)
+
+# Get the smtphost via occ
+smtphost = occget(["config:system:get","mail_smtphost"])
+
+# Get the smarthost
+if 'SMTP_HOST' in smarthost:
+    smtpsmarthost=smarthost['SMTP_HOST']
+else:
+    smtpsmarthost=""
+
+# Compare occ with smarthost settings and set the internal_smarthost variable accordingly
+if smtphost == smtpsmarthost:
+    config["internal_smarthost"] = False
+else:
+    config["internal_smarthost"] = True
+
+# Write config.json
+with open('config.json', 'w') as cfp:
+    cfp.write(json.dumps(config))
diff --git a/tests/nextcloud.robot b/tests/nextcloud.robot
index 9d0c8a71..e75d8714 100644
--- a/tests/nextcloud.robot
+++ b/tests/nextcloud.robot
@@ -10,7 +10,7 @@ Check if nextcloud is installed correctly
     Set Suite Variable    ${module_id}    ${output.module_id}
 
 Check if nextcloud can be configured
-    ${out}  ${err}  ${rc} =    Execute Command    api-cli run module/${module_id}/configure-module --data '{"host": "nextcloud.dom.test", "lets_encrypt": false, "domain": "", "password": "Nethesis,1234"}'
+    ${out}  ${err}  ${rc} =    Execute Command    api-cli run module/${module_id}/configure-module --data '{"host": "nextcloud.dom.test", "lets_encrypt": false, "domain": "", "password": "Nethesis,1234", "internal_smarthost": false}'
     ...    return_rc=True  return_stdout=True  return_stderr=True
     Should Be Equal As Integers    ${rc}  0
 
diff --git a/ui/public/i18n/en/translation.json b/ui/public/i18n/en/translation.json
index 7b95b8d4..d15a4c63 100644
--- a/ui/public/i18n/en/translation.json
+++ b/ui/public/i18n/en/translation.json
@@ -46,7 +46,8 @@
         "host_placeholder": "E.g. mynextcloud.example.org",
         "admin_password_tooltip": "The user 'admin' is the internal administrator of Nextcloud. This password is used to authenticate the 'admin' user in the Nextcloud web interface.",
         "host_pattern": "Must be a valid fully qualified domain name",
-        "host_format": "Must be a valid fully qualified domain name"
+        "host_format": "Must be a valid fully qualified domain name",
+        "internal_smarthost": "Manage email sending from Nextcloud admin panel"
     },
     "about": {
         "title": "About"
diff --git a/ui/src/views/Settings.vue b/ui/src/views/Settings.vue
index 39ecd033..571f84cb 100644
--- a/ui/src/views/Settings.vue
+++ b/ui/src/views/Settings.vue
@@ -111,6 +111,20 @@
               ref="domain"
             >
             </NsComboBox>
+            <NsToggle
+              value="internalSmarthost"
+              :label="$t('settings.internal_smarthost')"
+              v-model="internalSmarthost"
+              :disabled="loadingUi"
+              class="mg-bottom"
+            >
+              <template slot="text-left">{{
+                $t("settings.disabled")
+              }}</template>
+              <template slot="text-right">{{
+                $t("settings.enabled")
+              }}</template>
+            </NsToggle>
             <template v-if="is_collabora && installed">
               <NsComboBox
                 v-model.trim="collabora_host"
@@ -241,6 +255,7 @@ export default {
       host: "",
       isLetsEncryptEnabled: false,
       isLetsEncryptCurrentlyEnabled: false,
+      internalSmarthost: false,
       collabora_host: "",
       domain: "",
       password: "Nethesis,1234",
@@ -490,6 +505,7 @@ export default {
             host: this.host,
             lets_encrypt: this.isLetsEncryptEnabled,
             domain: this.domain === "-" ? "" : this.domain,
+            internal_smarthost: this.internalSmarthost,
             is_collabora: this.is_collabora,
             collabora_host: this.collabora_host,
             tls_verify_collabora: this.tls_verify_collabora,
@@ -521,6 +537,7 @@ export default {
       this.host = config.host;
       this.isLetsEncryptEnabled = config.lets_encrypt;
       this.isLetsEncryptCurrentlyEnabled = config.lets_encrypt;
+      this.internalSmarthost = config.internal_smarthost;
       this.running = config.running;
       this.installed = config.installed;
       this.is_collabora = config.is_collabora;