diff --git a/client/src/App.vue b/client/src/App.vue
index 9110b82..39c0ada 100644
--- a/client/src/App.vue
+++ b/client/src/App.vue
@@ -52,7 +52,7 @@
         </div>
       </nav>
 
-      <RouterView :userPermissions="loggedInUserInfo?.permissions" />
+      <RouterView :userPermissions="loggedInUserInfo?.permissions ?? DEFAULT_ROLE" />
     </div>
     <footer class="page-footer">
       <div class="container">
@@ -118,6 +118,7 @@ import { saveIdToken } from "@client/util/storage.js";
 import { faGithub } from "@fortawesome/free-brands-svg-icons";
 import { faExternalLink } from "@fortawesome/free-solid-svg-icons";
 import type { AppSettingsDto, LoggedInUserInfo } from "@fumix/fu-blog-common";
+import { DEFAULT_ROLE } from "@fumix/fu-blog-common";
 import { onMounted, ref, watch } from "vue";
 import { useI18n } from "vue-i18n";
 import { useRoute, useRouter } from "vue-router";
diff --git a/client/src/i18n/de.json b/client/src/i18n/de.json
index fdf18a4..f5fbfb2 100644
--- a/client/src/i18n/de.json
+++ b/client/src/i18n/de.json
@@ -73,7 +73,7 @@
       "not-available": {
         "title": "Post nicht vorhanden",
         "message": "Der Post ist nicht verfügbar oder wurde gelöscht. Sie können mit dem Button zur Startseite zurück, oder nutzen sie die Suchfunktion um einen bestimmten Post zu finden."
-      } 
+      }
     }
   },
   "admin": {
@@ -105,7 +105,8 @@
         "email": "E-mail",
         "username": "Benutzername",
         "fullname": "Dein Name"
-      }
+      },
+      "username-requirements": "Der Benutzername muss zwischen {min} und {max} Zeichen lang sein (ist {length} Zeichen lang) und darf nur aus den Buchstaben a-z/A-Z, den Zahlen 0-9 und den Zeichen ._- bestehen."
     },
     "user_not_found": "Benutzer nicht gefunden."
   }
diff --git a/client/src/i18n/en.json b/client/src/i18n/en.json
index c9353d2..61729f5 100644
--- a/client/src/i18n/en.json
+++ b/client/src/i18n/en.json
@@ -101,8 +101,9 @@
         "email": "Email",
         "username": "Username",
         "fullname": "Your name"
-      }
+      },
+      "username-requirements": "The username must be between 3 and 32 characters long and can only consist of letters a-z/A-Z, digits 0-9 and characters ._-"
     },
     "user_not_found": "User not found."
   }
-}
\ No newline at end of file
+}
diff --git a/client/src/util/api-client.ts b/client/src/util/api-client.ts
index 408d3b3..adb2f79 100644
--- a/client/src/util/api-client.ts
+++ b/client/src/util/api-client.ts
@@ -142,7 +142,7 @@ export class PostEndpoints {
 
   static async findPosts(pageIndex: number, itemsPerPage = 12, search: string | undefined = undefined, operator: "and" | "or" = "and") {
     return callServer<void, JsonMimeType, { data: [PublicPost[], number | null] }>(
-      `/api/posts/page/${pageIndex}/count/${itemsPerPage}${search ? `/search/${encodeURIComponent(search)}/operator/${operator}` : ""}###`,
+      `/api/posts/page/${pageIndex}/count/${itemsPerPage}${search ? `/search/${encodeURIComponent(search)}/operator/${operator}` : ""}`,
       "GET",
       "application/json",
       null,
diff --git a/server/src/routes/auth.ts b/server/src/routes/auth.ts
index fa3eb40..9c1b266 100644
--- a/server/src/routes/auth.ts
+++ b/server/src/routes/auth.ts
@@ -11,6 +11,7 @@ import {
   OAuthUserInfoDto,
   UserInfoOAuthToken,
 } from "@fumix/fu-blog-common";
+import { sendNotificationEmailAboutNewRegistration } from "../service/email-service.js";
 import express, { Request, Response, Router } from "express";
 import fetch from "node-fetch";
 import { BaseClient, Issuer, TokenSet } from "openid-client";
@@ -232,9 +233,10 @@ router.post("/userinfo/register", async (req, res, next) => {
                     oauthId: oauthUserId,
                     user,
                   };
-                  await mgr
-                    .insert(OAuthAccountEntity, [oauthAccount])
-                    .then((it) => logger.info("New OAuth account created: " + JSON.stringify(oauthAccount)));
+                  await mgr.insert(OAuthAccountEntity, [oauthAccount]).then((it) => {
+                    sendNotificationEmailAboutNewRegistration(oauthAccount.user.username);
+                    logger.info("New OAuth account created: " + JSON.stringify(oauthAccount));
+                  });
                 })
                 .then(async () => {
                   const result: OAuthUserInfoDto = {
diff --git a/server/src/routes/posts.ts b/server/src/routes/posts.ts
index a20b41c..bdbc7bf 100644
--- a/server/src/routes/posts.ts
+++ b/server/src/routes/posts.ts
@@ -6,7 +6,7 @@ import {
   NewPostRequestDto,
   PostRequestDto,
 } from "@fumix/fu-blog-common";
-import logger from "@server/logger.js";
+import logger from "../logger.js";
 import express, { NextFunction, Request, Response, Router } from "express";
 import { In } from "typeorm";
 import { AppDataSource } from "../data-source.js";
diff --git a/server/src/service/email-service.ts b/server/src/service/email-service.ts
new file mode 100644
index 0000000..b7d7a83
--- /dev/null
+++ b/server/src/service/email-service.ts
@@ -0,0 +1,56 @@
+import console from "console";
+import { createTransport } from "nodemailer";
+import { AppDataSource } from "../data-source.js";
+import { UserEntity } from "../entity/User.entity.js";
+import logger from "../logger.js";
+import { ClientSettings, EmailSettings } from "../settings.js";
+
+export async function sendNotificationEmailAboutNewRegistration(newUsername: string) {
+  const admin_emails = await AppDataSource.manager
+    .getRepository(UserEntity)
+    .createQueryBuilder("find all admins")
+    .where("roles @> :role", { role: ["ADMIN"] }) // https://www.postgresql.org/docs/16/functions-array.html#ARRAY-OPERATORS-TABLE
+    .getMany()
+    .then((users) => {
+      console.log("Found users", users);
+      return users.map((user) => user.email);
+    })
+    .catch((e) => {
+      console.error("Failed to get admins", e);
+      return [];
+    });
+
+  if (admin_emails.length <= 0) {
+    logger.warn(`There are no admins yet. No notification email is sent about new user '${newUsername}'.`);
+  } else {
+    logger.debug(`Sending notification email about registration of new user '${newUsername}' to ${admin_emails.join(", ")}`);
+
+    await sendEmail(
+      admin_emails,
+      "New user registered",
+      `Hi admins,
+a new user '${encodeURIComponent(newUsername)}' registered at ${ClientSettings.BASE_URL} .
+Visit ${ClientSettings.BASE_URL}/administration in order to give them some permissions.
+
+Kind regards,
+Your fuBlog`,
+    );
+  }
+}
+
+function sendEmail(to: string[], subject: string, text: string) {
+  if (!(EmailSettings.SMTP_HOST ?? EmailSettings.SMTP_PORT)) {
+    throw new Error("No SMTP email server set! Cannot send email.");
+  }
+
+  createTransport(EmailSettings.SMTP_OPTIONS)
+    .sendMail({
+      from: "fublog@fumix.de",
+      to,
+      subject,
+      text,
+    })
+    .catch(() => {
+      logger.error("Failed to send email notification!");
+    });
+}