feat(mail/delivery): add error-count based blocking to rate limiter; improve test SMTP server port selection; add tsbuild scripts and devDependency; remove stale backup file

ts/mail/delivery/smtpserver/smtp-server.ts

@@ -185,12 +185,12 @@ export class SmtpServer implements ISmtpServer {
           reject(new Error('Server not initialized'));
           return;
         }
-        
+
         this.server.listen(this.options.port, this.options.host, () => {
           SmtpLogger.info(`SMTP server listening on ${this.options.host || '0.0.0.0'}:${this.options.port}`);
           resolve();
         });
-        
+
         this.server.on('error', reject);
       });
       
@@ -458,7 +458,7 @@ export class SmtpServer implements ISmtpServer {
   public getEmailServer(): UnifiedEmailServer {
     return this.emailServer;
   }
-  
+
   /**
    * Check if the server is running
    * @returns Whether the server is running