diff --git a/modoboa_installer/scripts/amavis.py b/modoboa_installer/scripts/amavis.py
index 14e4b1f..8988695 100644
--- a/modoboa_installer/scripts/amavis.py
+++ b/modoboa_installer/scripts/amavis.py
@@ -42,13 +42,14 @@ class Amavis(base.Installer):
     def get_config_files(self):
         """Return appropriate config files."""
         if package.backend.FORMAT == "deb":
-            amavis_custom_configuration = os.path.join(
-                self.restore, "custom/99-custom")
-            if self.restore and os.path.isfile(amavis_custom_configuration):
-                utils.copy_file(amavis_custom_configuration, os.path.join(
-                    self.config_dir, "/conf.d"))
-                utils.printcolor(
-                    "Custom amavis configuration restored.", utils.GREEN)
+            if self.restore is not None:
+                amavis_custom_configuration = os.path.join(
+                    self.restore, "custom/99-custom")
+                if os.path.isfile(amavis_custom_configuration):
+                    utils.copy_file(amavis_custom_configuration, os.path.join(
+                        self.config_dir, "conf.d"))
+                    utils.printcolor(
+                        "Custom amavis configuration restored.", utils.GREEN)
             return [
                 "conf.d/05-node_id", "conf.d/15-content_filter_mode",
                 "conf.d/50-user"]
diff --git a/modoboa_installer/scripts/backup.py b/modoboa_installer/scripts/backup.py
index 64b3add..a434a94 100644
--- a/modoboa_installer/scripts/backup.py
+++ b/modoboa_installer/scripts/backup.py
@@ -22,6 +22,7 @@ class Backup:
         |--> { (copy of) /etc/postfix/custom_whitelist.cidr }
         |--> { (copy of) dkim folder }
             |--> {dkim.pem}...
+        |--> { (copy of) radicale home_dir }
     ||--> databases
         |--> modoboa.sql
         |--> { amavis.sql }
@@ -144,6 +145,7 @@ class Backup:
     def custom_config_backup(self):
         """Custom config :
         - DKIM keys: {{keys_storage_dir}}
+        - Radicale collection (calendat, contacts): {{home_dir}}
         - Amavis : /etc/amavis/conf.d/99-custom
         - Postwhite : /etc/postwhite.conf
         Feel free to suggest to add others!"""
@@ -158,9 +160,20 @@ class Backup:
                 self.config.getboolean("opendkim", "enabled")):
             dkim_keys = self.config.get(
                 "opendkim", "keys_storage_dir", fallback="/var/lib/dkim")
-            shutil.copytree(dkim_keys, os.path.join(custom_path, "dkim"))
-            utils.printcolor(
-                "DKIM keys saved!", utils.GREEN)
+            if os.path.isdir(dkim_keys):
+                shutil.copytree(dkim_keys, os.path.join(custom_path, "dkim"))
+                utils.printcolor(
+                    "DKIM keys saved!", utils.GREEN)
+
+        # Radicale Collections
+        if (self.config.has_option("radicale", "enabled") and
+                self.config.getboolean("radicale", "enabled")):
+            radicale_backup = os.path.join(self.config.get(
+                "radicale", "home_dir", fallback="/srv/radicale"), "collections")
+            if os.path.isdir(radicale_backup):
+                shutil.copytree(radicale_backup, os.path.join(
+                    custom_path, "radicale"))
+                utils.printcolor("Radicale files saved", utils.GREEN)
 
         # AMAVIS
         if (self.config.has_option("amavis", "enabled") and
diff --git a/modoboa_installer/scripts/dovecot.py b/modoboa_installer/scripts/dovecot.py
index 3bb2518..03cda78 100644
--- a/modoboa_installer/scripts/dovecot.py
+++ b/modoboa_installer/scripts/dovecot.py
@@ -89,7 +89,7 @@ class Dovecot(base.Installer):
     def post_run(self):
         """Additional tasks."""
         mail_dir = os.path.join(self.restore, "mails/")
-        if self.restore and len(os.listdir(mail_dir)) > 0:
+        if self.restore is not None and len(os.listdir(mail_dir)) > 0:
             utils.printcolor(
                 "Copying mail backup over dovecot directory.", utils.GREEN)
 
@@ -103,7 +103,7 @@ class Dovecot(base.Installer):
                 for filename in filenames:
                     shutil.chown(os.path.join(dirpath, filename),
                                  self.user, self.user)
-        elif self.restore:
+        elif self.restore is not None:
             utils.printcolor(
                 "It seems that mails were not backed up, skipping mail restoration.", utils.MAGENTA)
 
diff --git a/modoboa_installer/scripts/modoboa.py b/modoboa_installer/scripts/modoboa.py
index 8821016..9719782 100644
--- a/modoboa_installer/scripts/modoboa.py
+++ b/modoboa_installer/scripts/modoboa.py
@@ -193,7 +193,7 @@ class Modoboa(base.Installer):
             self.config.get("amavis", "dbname"), self.dbuser)
 
     def get_sql_schema_path(self):
-        if self.restore:
+        if self.restore is not None:
             db_dump_path = self._restore_database_dump("modoboa")
             if db_dump_path is not None:
                 return db_dump_path
diff --git a/modoboa_installer/scripts/opendkim.py b/modoboa_installer/scripts/opendkim.py
index 9875a93..1dec655 100644
--- a/modoboa_installer/scripts/opendkim.py
+++ b/modoboa_installer/scripts/opendkim.py
@@ -46,6 +46,18 @@ class Opendkim(base.Installer):
                     stat.S_IROTH | stat.S_IXOTH,
                     target[1], target[2]
                 )
+        # Restore dkim keys from backup if restoring
+        if self.restore is not None:
+            dkim_keys_backup = os.path.join(
+                self.restore, "custom/dkim")
+            if os.path.isdir(dkim_keys_backup):
+                for file in os.listdir(dkim_keys_backup):
+                    file_path = os.path.join(dkim_keys_backup, file)
+                    if os.path.isfile(file_path):
+                        utils.copy_file(file_path, self.config.get(
+                            "opendkim", "keys_storage_dir", fallback="/var/lib/dkim"))
+                utils.printcolor(
+                    "DKIM keys restored from backup", utils.GREEN)
         super(Opendkim, self).install_config_files()
 
     def get_template_context(self):
diff --git a/modoboa_installer/scripts/postwhite.py b/modoboa_installer/scripts/postwhite.py
index 4a36182..ec54639 100644
--- a/modoboa_installer/scripts/postwhite.py
+++ b/modoboa_installer/scripts/postwhite.py
@@ -47,13 +47,15 @@ class Postwhite(base.Installer):
         self.install_from_archive(SPF_TOOLS_REPOSITORY, install_dir)
         postw_dir = self.install_from_archive(
             POSTWHITE_REPOSITORY, install_dir)
-        postwhite_backup_configuration = os.path.join(
-            self.restore, "custom/postwhite.conf")
-        if self.restore and os.path.isfile(postwhite_backup_configuration):
-            utils.copy_file(postwhite_backup_configuration, "/etc")
-            utils.printcolor(
-                "postwhite.conf restored from backup", utils.GREEN)
-        else:
-            utils.copy_file(os.path.join(postw_dir, "postwhite.conf"), "/etc")
+        # Attempt to restore config file from backup
+        if self.restore is not None:
+            postwhite_backup_configuration = os.path.join(
+                self.restore, "custom/postwhite.conf")
+            if os.path.isfile(postwhite_backup_configuration):
+                utils.copy_file(postwhite_backup_configuration, self.config_dir)
+                utils.printcolor(
+                    "postwhite.conf restored from backup", utils.GREEN)
+            else:
+                utils.copy_file(os.path.join(postw_dir, "postwhite.conf"), self.config_dir)
         postw_bin = os.path.join(postw_dir, "postwhite")
         utils.exec_cmd("{} /etc/postwhite.conf".format(postw_bin))
diff --git a/modoboa_installer/scripts/radicale.py b/modoboa_installer/scripts/radicale.py
index 889403f..df6e38b 100644
--- a/modoboa_installer/scripts/radicale.py
+++ b/modoboa_installer/scripts/radicale.py
@@ -1,6 +1,7 @@
 """Radicale related tasks."""
 
 import os
+import shutil
 import stat
 
 from .. import package
@@ -70,6 +71,17 @@ class Radicale(base.Installer):
                 stat.S_IROTH | stat.S_IXOTH,
                 0, 0
             )
+        # Attempt to restore radicale collections from backup
+        if self.restore is not None:
+            radicale_backup = os.path.join(
+                self.restore, "custom/radicale")
+            if os.path.isdir(radicale_backup):
+                restore_target = os.path.join(self.home_dir, "collections")
+                if os.path.isdir(restore_target):
+                    shutil.rmtree(restore_target)
+                shutil.copytree(radicale_backup, restore_target)
+                utils.printcolor(
+                    "Radicale collections restored from backup", utils.GREEN)
         super(Radicale, self).install_config_files()
 
     def post_run(self):
diff --git a/modoboa_installer/scripts/spamassassin.py b/modoboa_installer/scripts/spamassassin.py
index e5fd3a3..f47ebd8 100644
--- a/modoboa_installer/scripts/spamassassin.py
+++ b/modoboa_installer/scripts/spamassassin.py
@@ -25,7 +25,7 @@ class Spamassassin(base.Installer):
 
     def get_sql_schema_path(self):
         """Return SQL schema."""
-        if self.restore:
+        if self.restore is not None:
             db_dump_path = self._restore_database_dump("spamassassin")
             if db_dump_path is not None:
                 return db_dump_path