Adding answer for versions of Angular >= 4.3 (including 11) with new HttpClient that replaces http

import {HttpClientModule} from '@angular/common/http'; // Notice it is imported from @angular/common/http instead of @angular/http

How to get response code or any other header:

http.get(
   `${this.baseUrl}users/activate?mailToken=${mailToken}`,
    {observe: 'response'}
)
  .subscribe(response => {
    
    // You can access status:
    console.log(response.status);
    
    // Or any other header:
    console.log(response.headers.get('X-Custom-Header'));
  });

As noted in the comment by @Rbk,

The object {observe: 'response'} is what makes the full response object available.

Check Documentation

Just modify your code as following to store your responseStatus in a field :

responseStatus: number;

//This method must return the status of the http response
confirmEmail(mailToken):Observable<String> {
//Edited for working with HttpClient on Angular >= 4.3
  return this.http.get(this.baseUrl+"users/activate?mailToken="+mailToken, {observe: 'response'})
                 .map((response: Response) => {
                   this.responseStatus = response.status;
                   return this.extractData(response);
                 }
                 .catch(this.handleError);

}

And then display it in your component HTML template :

<p class='responseStatus'>{{responseStatus}}</p>

Its simple !!

Inside your extractData function

extractData (res){
//res.status  will be your status code
// res.statusText  will be your status Text
}