diff --git a/bizmatch-server/src/mail/mail.controller.ts b/bizmatch-server/src/mail/mail.controller.ts
index 1377b13..1ce880c 100644
--- a/bizmatch-server/src/mail/mail.controller.ts
+++ b/bizmatch-server/src/mail/mail.controller.ts
@@ -1,13 +1,12 @@
 import { Body, Controller, Post } from '@nestjs/common';
-import { User } from 'src/models/db.model.js';
-import { MailInfo } from 'src/models/main.model.js';
+import { ErrorResponse, MailInfo } from 'src/models/main.model.js';
 import { MailService } from './mail.service.js';
 
 @Controller('mail')
 export class MailController {
   constructor(private mailService: MailService) {}
   @Post()
-  sendEMail(@Body() mailInfo: MailInfo): Promise<User> {
+  sendEMail(@Body() mailInfo: MailInfo): Promise<void | ErrorResponse> {
     return this.mailService.sendInquiry(mailInfo);
   }
 }
diff --git a/bizmatch-server/src/mail/mail.service.ts b/bizmatch-server/src/mail/mail.service.ts
index 1fd90e9..2da58d6 100644
--- a/bizmatch-server/src/mail/mail.service.ts
+++ b/bizmatch-server/src/mail/mail.service.ts
@@ -2,8 +2,7 @@ import { MailerService } from '@nestjs-modules/mailer';
 import { Injectable } from '@nestjs/common';
 import path, { join } from 'path';
 import { fileURLToPath } from 'url';
-import { User } from '../models/db.model.js';
-import { MailInfo } from '../models/main.model.js';
+import { ErrorResponse, MailInfo, isEmpty } from '../models/main.model.js';
 import { UserService } from '../user/user.service.js';
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.dirname(__filename);
@@ -15,10 +14,13 @@ export class MailService {
     private userService: UserService,
   ) {}
 
-  async sendInquiry(mailInfo: MailInfo): Promise<User> {
+  async sendInquiry(mailInfo: MailInfo): Promise<void | ErrorResponse> {
     //const user = await this.authService.getUser(mailInfo.userId) as KeycloakUser;
     const user = await this.userService.getUserByMail(mailInfo.email);
     console.log(JSON.stringify(user));
+    if (isEmpty(mailInfo.sender.name)) {
+      return { fields: [{ fieldname: 'name', message: 'Required' }] };
+    }
     await this.mailerService.sendMail({
       to: user.email,
       from: '"Bizmatch Team" <info@bizmatch.net>', // override default from
@@ -38,6 +40,5 @@ export class MailService {
         url: mailInfo.url,
       },
     });
-    return user;
   }
 }
diff --git a/bizmatch-server/src/models/main.model.ts b/bizmatch-server/src/models/main.model.ts
index 0fcc6f3..5926c19 100644
--- a/bizmatch-server/src/models/main.model.ts
+++ b/bizmatch-server/src/models/main.model.ts
@@ -165,3 +165,42 @@ export interface ImageProperty {
   code: string;
   name: string;
 }
+export interface ErrorResponse {
+  fields?: FieldError[];
+  general?: string[];
+}
+export interface FieldError {
+  fieldname: string;
+  message: string;
+}
+export function isEmpty(value: any): boolean {
+  // Check for undefined or null
+  if (value === undefined || value === null) {
+    return true;
+  }
+
+  // Check for empty string or string with only whitespace
+  if (typeof value === 'string') {
+    return value.trim().length === 0;
+  }
+
+  // Check for number and NaN
+  if (typeof value === 'number') {
+    return isNaN(value);
+  }
+
+  // If it's not a string or number, it's not considered empty by this function
+  return false;
+}
+export function emailToDirName(email: string): string {
+  // Entferne ungültige Zeichen und ersetze sie durch Unterstriche
+  const sanitizedEmail = email.replace(/[^a-zA-Z0-9_-]/g, '_');
+
+  // Entferne führende und nachfolgende Unterstriche
+  const trimmedEmail = sanitizedEmail.replace(/^_+|_+$/g, '');
+
+  // Ersetze mehrfache aufeinanderfolgende Unterstriche durch einen einzelnen Unterstrich
+  const normalizedEmail = trimmedEmail.replace(/_+/g, '_');
+
+  return normalizedEmail;
+}
diff --git a/bizmatch/src/app/pages/details/details-business-listing/details-business-listing.component.html b/bizmatch/src/app/pages/details/details-business-listing/details-business-listing.component.html
index 336234b..5bec8a6 100644
--- a/bizmatch/src/app/pages/details/details-business-listing/details-business-listing.component.html
+++ b/bizmatch/src/app/pages/details/details-business-listing/details-business-listing.component.html
@@ -90,12 +90,14 @@
                 <label for="notes" class="font-medium text-900">Questions/Comments</label>
                 <textarea id="notes" pInputTextarea [autoResize]="true" [rows]="5" [(ngModel)]="mailinfo.sender.comments"></textarea>
               </div>
+              @if(listingUser){
               <div class="surface-border mb-4 col-12 flex align-items-center">
                 Listing by &nbsp;<a routerLink="/details-user/{{ listingUser.id }}" class="mr-2">{{ listingUser.firstname }} {{ listingUser.lastname }}</a>
                 @if(listingUser.hasCompanyLogo){
                 <img src="{{ env.imageBaseUrl }}/pictures/logo/{{ listingUser.id }}.avif?_ts={{ ts }}" class="mr-5 lg:mb-0" style="height: 30px; max-width: 100px" />
                 }
               </div>
+              }
             </div>
             <button pButton pRipple label="Submit" icon="pi pi-file" class="w-auto" (click)="mail()"></button>
           </div>
diff --git a/bizmatch/src/app/pages/details/details-commercial-property-listing/details-commercial-property-listing.component.html b/bizmatch/src/app/pages/details/details-commercial-property-listing/details-commercial-property-listing.component.html
index 8f826f6..0de73bd 100644
--- a/bizmatch/src/app/pages/details/details-commercial-property-listing/details-commercial-property-listing.component.html
+++ b/bizmatch/src/app/pages/details/details-commercial-property-listing/details-commercial-property-listing.component.html
@@ -61,7 +61,7 @@
             <div class="grid formgrid p-fluid">
               <div class="field mb-4 col-12 md:col-6">
                 <label for="name" class="font-medium text-900">Your Name</label>
-                <input id="name" type="text" pInputText [(ngModel)]="mailinfo.sender.name" />
+                <input [ngClass]="{ 'ng-invalid': containsError('name'), 'ng-dirty': containsError('name') }" id="name" type="text" pInputText [(ngModel)]="mailinfo.sender.name" />
               </div>
               <div class="field mb-4 col-12 md:col-6">
                 <label for="email" class="font-medium text-900">Your Email</label>
@@ -80,12 +80,14 @@
                 <label for="notes" class="font-medium text-900">Questions/Comments</label>
                 <textarea id="notes" pInputTextarea [autoResize]="true" [rows]="5" [(ngModel)]="mailinfo.sender.comments"></textarea>
               </div>
+              @if(listingUser){
               <div class="surface-border mb-4 col-12 flex align-items-center">
                 Listing by &nbsp;<a routerLink="/details-user/{{ listingUser.id }}" class="mr-2">{{ listingUser.firstname }} {{ listingUser.lastname }}</a>
                 @if(listingUser.hasCompanyLogo){
                 <img src="{{ env.imageBaseUrl }}/pictures/logo/{{ listingUser.id }}.avif?_ts={{ ts }}" class="mr-5 lg:mb-0" style="height: 30px; max-width: 100px" />
                 }
               </div>
+              }
             </div>
             <button pButton pRipple label="Submit" icon="pi pi-file" class="w-auto" (click)="mail()"></button>
           </div>
diff --git a/bizmatch/src/app/pages/details/details-commercial-property-listing/details-commercial-property-listing.component.ts b/bizmatch/src/app/pages/details/details-commercial-property-listing/details-commercial-property-listing.component.ts
index 5e0918b..f980489 100644
--- a/bizmatch/src/app/pages/details/details-commercial-property-listing/details-commercial-property-listing.component.ts
+++ b/bizmatch/src/app/pages/details/details-commercial-property-listing/details-commercial-property-listing.component.ts
@@ -6,7 +6,7 @@ import { MessageService } from 'primeng/api';
 import { GalleriaModule } from 'primeng/galleria';
 import { lastValueFrom } from 'rxjs';
 import { CommercialPropertyListing, User } from '../../../../../../bizmatch-server/src/models/db.model';
-import { KeycloakUser, ListingCriteria, MailInfo } from '../../../../../../bizmatch-server/src/models/main.model';
+import { ErrorResponse, KeycloakUser, ListingCriteria, MailInfo } from '../../../../../../bizmatch-server/src/models/main.model';
 import { environment } from '../../../../environments/environment';
 import { HistoryService } from '../../../services/history.service';
 import { ListingsService } from '../../../services/listings.service';
@@ -54,6 +54,7 @@ export class DetailsCommercialPropertyListingComponent {
   description: SafeHtml;
   ts = new Date().getTime();
   env = environment;
+  errorResponse: ErrorResponse;
   constructor(
     private activatedRoute: ActivatedRoute,
     private listingsService: ListingsService,
@@ -85,7 +86,15 @@ export class DetailsCommercialPropertyListingComponent {
     this.mailinfo.email = this.listingUser.email;
     this.mailinfo.userId = this.listing.userId;
     this.mailinfo.listing = this.listing;
-    await this.mailService.mail(this.mailinfo);
-    this.messageService.add({ severity: 'info', summary: 'Confirmed', detail: 'Your message has been sent to the creator of the listing', life: 3000 });
+    const result = await this.mailService.mail(this.mailinfo);
+    if (result) {
+      this.errorResponse = result as ErrorResponse;
+    } else {
+      this.errorResponse = null;
+      this.messageService.add({ severity: 'info', summary: 'Confirmed', detail: 'Your message has been sent to the creator of the listing', life: 3000 });
+    }
+  }
+  containsError(fieldname: string) {
+    return this.errorResponse?.fields.map(f => f.fieldname).includes(fieldname);
   }
 }
diff --git a/bizmatch/src/app/services/mail.service.ts b/bizmatch/src/app/services/mail.service.ts
index 96b22eb..33ffed1 100644
--- a/bizmatch/src/app/services/mail.service.ts
+++ b/bizmatch/src/app/services/mail.service.ts
@@ -1,18 +1,17 @@
-import { Injectable } from '@angular/core';
 import { HttpClient } from '@angular/common/http';
-import { environment } from '../../environments/environment';
+import { Injectable } from '@angular/core';
 import { lastValueFrom } from 'rxjs';
-import { MailInfo } from '../../../../bizmatch-server/src/models/main.model';
+import { ErrorResponse, MailInfo } from '../../../../bizmatch-server/src/models/main.model';
+import { environment } from '../../environments/environment';
 
 @Injectable({
-  providedIn: 'root'
+  providedIn: 'root',
 })
 export class MailService {
-
   private apiBaseUrl = environment.apiBaseUrl;
-  constructor(private http: HttpClient) { }
+  constructor(private http: HttpClient) {}
 
-  async mail(mailinfo:MailInfo):Promise<void>{
-    await lastValueFrom(this.http.post(`${this.apiBaseUrl}/bizmatch/mail`,mailinfo));
+  async mail(mailinfo: MailInfo): Promise<void | ErrorResponse> {
+    return await lastValueFrom(this.http.post(`${this.apiBaseUrl}/bizmatch/mail`, mailinfo));
   }
 }