#204: started moving concurrent helper classes to a separate package

src/main/java/org/simplejavamail/mailer/internal/mailsender/MailSender.java

@@ -6,6 +6,7 @@
 import org.simplejavamail.email.Recipient;
 import org.simplejavamail.mailer.MailerGenericBuilder;
 import org.simplejavamail.mailer.config.TransportStrategy;
+import org.simplejavamail.mailer.internal.mailsender.concurrent.NamedRunnable;
 import org.simplejavamail.mailer.internal.socks.AuthenticatingSocks5Bridge;
 import org.simplejavamail.mailer.internal.socks.SocksProxyConfig;
 import org.simplejavamail.mailer.internal.socks.socks5server.AnonymousSocks5Server;
@@ -196,16 +197,11 @@ the proxy bridge server (or connection pool in async mode) while a non-async ema
 				executor = Executors.newFixedThreadPool(operationalConfig.getThreadPoolSize());
 			}
 			configureSessionWithTimeout(session, operationalConfig.getSessionTimeout());
-			executor.execute(new Runnable() {
+			executor.execute(new NamedRunnable("sendMail process") {
 				@Override
 				public void run() {
 					sendMailClosure(session, email);
 				}
-
-				@Override
-				public String toString() {
-					return "sendMail process";
-				}
 			});
 		} else {
 			sendMailClosure(session, email);

src/main/java/org/simplejavamail/mailer/internal/mailsender/concurrent/NamedRunnable.java

@@ -0,0 +1,15 @@
+package org.simplejavamail.mailer.internal.mailsender.concurrent;
+
+public abstract class NamedRunnable implements Runnable {
+
+	private final String name;
+
+	public NamedRunnable(String name) {
+		this.name = name;
+	}
+
+	@Override
+	public String toString() {
+		return name;
+	}
+}