feat: adding email notification when certian revalidation threshold is met

• feat: adding email notification when certian revalidation threshold is met

Resolves #149 (closed)

src/main/java/org/eclipsefoundation/git/eca/config/MailerConfig.java

+/**
+ * Copyright (c) 2025 Eclipse Foundation
+ *
+ * This program and the accompanying materials are made available under the terms of the Eclipse
+ * Public License 2.0 which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * Author: Jordi Gómez <jordi.gomez@eclipse-foundation.org>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.eclipsefoundation.git.eca.config;
+
+import java.util.List;
+import java.util.Optional;
+
+import io.smallrye.config.ConfigMapping;
+
+/**
+ * Represents configuration for the default mailer service.
+ * 
+ * @author Martin Lowe
+ *
+ */
+@ConfigMapping(prefix = "eclipse.mailer")
+public interface MailerConfig {
+
+  public RevalidationAlert revalidationAlert();
+
+  /**
+   * This interface defines the contract for specifying recipients and message configuration when
+   * sending revalidation alerts within the ECA validation process.
+   */
+  public interface RevalidationAlert {
+    public List<String> to();
+
+    public MessageConfiguration authorMessage();
+  }
+
+  public interface MessageConfiguration {
+    public Optional<String> replyTo();
+
+    public Optional<List<String>> bcc();
+  }
+}