diff --git a/li.strolch.utils/src/main/java/li/strolch/utils/SmtpMailer.java b/li.strolch.utils/src/main/java/li/strolch/utils/SmtpMailer.java
index 3298dbb70..74b1ccac6 100644
--- a/li.strolch.utils/src/main/java/li/strolch/utils/SmtpMailer.java
+++ b/li.strolch.utils/src/main/java/li/strolch/utils/SmtpMailer.java
@@ -2,13 +2,19 @@ package li.strolch.utils;
 
 import java.io.UnsupportedEncodingException;
 import java.text.MessageFormat;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
 import java.util.Properties;
+import java.util.Set;
+import java.util.stream.Collectors;
 
 import javax.mail.Message;
 import javax.mail.MessagingException;
 import javax.mail.PasswordAuthentication;
 import javax.mail.Session;
 import javax.mail.Transport;
+import javax.mail.internet.AddressException;
 import javax.mail.internet.InternetAddress;
 import javax.mail.internet.MimeMessage;
 
@@ -22,8 +28,8 @@ import org.slf4j.LoggerFactory;
  * The {@link Properties} required are as follows:
  * <ul>
  * <li><code>fromAddr</code> and <code>fromName</code> - defines the address from which the e-mail comes from</li>
- * <li><code>overrideRecipientAddr</code> and <code>overrideRecipientName</code> - if defined, overrides any recipient -
- * useful for testng purposes</li>
+ * <li><code>overrideRecipients</code> - if defined, overrides any recipients - useful for testng purposes</li>
+ * <li><code>recipientWhitelist</code> - if defined allows those e-mail addresses to not be overridden</li>
  * <li>username - the username to authenticate at the SMTP Server</li>
  * <li>password - the password to authenticate at the SMTP Server</li>
  * <li>auth - boolean to define if auth is to be done</li>
@@ -51,7 +57,7 @@ public class SmtpMailer {
 	public static void init(Properties properties) {
 		try {
 			instance = new SmtpMailer(properties);
-		} catch (UnsupportedEncodingException e) {
+		} catch (UnsupportedEncodingException | AddressException e) {
 			throw new RuntimeException("Failed to initialize Mailer due to " + e.getMessage(), e);
 		}
 	}
@@ -68,7 +74,8 @@ public class SmtpMailer {
 	}
 
 	private final InternetAddress from;
-	private final InternetAddress overrideRecipient;
+	private final InternetAddress[] overrideRecipients;
+	private final Set<InternetAddress> recipientWhitelist;
 	private final String username;
 	private final String password;
 	private final Properties props;
@@ -81,30 +88,49 @@ public class SmtpMailer {
 	 * 
 	 * @throws UnsupportedEncodingException
 	 *             if something goes wrong parsing the from or override addresses
+	 * @throws AddressException
+	 *             if something goes wrong parsing the from or override addresses
 	 */
-	private SmtpMailer(Properties properties) throws UnsupportedEncodingException {
+	private SmtpMailer(Properties properties) throws UnsupportedEncodingException, AddressException {
 
 		String fromAddr = properties.getProperty("fromAddr", null);
 		String fromName = properties.getProperty("fromName", null);
 		this.from = new InternetAddress(fromAddr, fromName);
 
-		if (properties.containsKey("overrideRecipientAddr")) {
-			String addr = properties.getProperty("overrideRecipientAddr", null);
-			String name = properties.getProperty("overrideRecipientName", null);
-			this.overrideRecipient = new InternetAddress(addr, name);
+		if (properties.containsKey("overrideRecipients")) {
+			String addr = properties.getProperty("overrideRecipients", null);
+			this.overrideRecipients = InternetAddress.parse(addr);
 		} else {
-			this.overrideRecipient = null;
+			this.overrideRecipients = null;
+		}
+
+		if (!properties.containsKey("recipientWhitelist")) {
+			this.recipientWhitelist = null;
+		} else {
+			String whiteListProp = properties.getProperty("recipientWhitelist");
+			this.recipientWhitelist = Arrays.stream(whiteListProp.split(",")) //
+					.map(s -> s.trim()) //
+					.map(s -> Arrays.asList(parseAddress(s))) //
+					.flatMap(List::stream) //
+					.collect(Collectors.toSet());
 		}
 
 		this.username = properties.getProperty("username", null);
 		this.password = properties.getProperty("password", null);
 
 		this.props = new Properties();
-		props.put("mail.smtp.auth", properties.getProperty("auth", null));
-		props.put("mail.smtp.starttls.enable", properties.getProperty("startTls", null));
-		props.put("mail.smtp.host", properties.getProperty("host", null));
-		props.put("mail.smtp.port", properties.getProperty("port", null));
+		this.props.put("mail.smtp.auth", properties.getProperty("auth", null));
+		this.props.put("mail.smtp.starttls.enable", properties.getProperty("startTls", null));
+		this.props.put("mail.smtp.host", properties.getProperty("host", null));
+		this.props.put("mail.smtp.port", properties.getProperty("port", null));
+	}
 
+	private InternetAddress[] parseAddress(String s) {
+		try {
+			return InternetAddress.parse(s);
+		} catch (AddressException e) {
+			throw new IllegalArgumentException("Failed to parse address: " + s, e);
+		}
 	}
 
 	/**
@@ -114,46 +140,81 @@ public class SmtpMailer {
 	 *            the subject of the e-mail
 	 * @param text
 	 *            the test of the e-mail
-	 * @param recipient
-	 *            the address to whom to send the e-mail
+	 * @param recipients
+	 *            the addresses to whom to send the e-mail. See {@link InternetAddress#parse(String)}
 	 */
-	public void sendMail(String subject, String text, String recipient) {
+	public void sendMail(String subject, String text, String recipients) {
 
 		try {
 
-			Session session = Session.getInstance(this.props, new javax.mail.Authenticator() {
-				protected PasswordAuthentication getPasswordAuthentication() {
-					return new PasswordAuthentication(SmtpMailer.this.username, SmtpMailer.this.password);
+			if (this.overrideRecipients == null) {
+
+				// no override, just send
+				send(subject, text, parseAddress(recipients));
+				logger.info(MessageFormat.format("Sent E-mail to {0}: {1}", recipients, subject));
+
+			} else if (this.recipientWhitelist == null) {
+
+				// override, with no white list, so send to override
+				text = "Override recipient. Original recipients: " + recipients + ".\n\n" + text;
+				send(subject, text, this.overrideRecipients);
+				logger.info(MessageFormat.format("Sent E-mail to override recipient {0}: {1}",
+						Arrays.asList(this.overrideRecipients).stream() //
+								.map(Object::toString) //
+								.collect(Collectors.joining(",")),
+						subject));
+
+			} else {
+
+				// override with whitelist, so we have to perhaps send to override and white list
+
+				Set<InternetAddress> allowList = new HashSet<>();
+				boolean needsOverrides = false;
+
+				for (InternetAddress recipient : parseAddress(recipients)) {
+					if (this.recipientWhitelist.contains(recipient))
+						allowList.add(recipient);
+					else
+						needsOverrides = true;
 				}
-			});
 
-			Message message = new MimeMessage(session);
-			message.setFrom(this.from);
-			if (this.overrideRecipient != null)
-				message.setRecipient(Message.RecipientType.TO, this.overrideRecipient);
-			else
-				message.addRecipients(Message.RecipientType.TO, InternetAddress.parse(recipient));
+				if (!allowList.isEmpty()) {
+					send(subject, text, parseAddress(recipients));
+					logger.info(MessageFormat.format("Sent E-mail to {0}: {1}", recipients, subject));
+				}
 
-			message.setSubject(subject);
+				if (needsOverrides) {
 
-			if (this.overrideRecipient != null)
-				text = "Override recipient. Original recipient " + recipient + ".\n\n" + text;
-			message.setText(text);
-
-			Transport.send(message);
-
-			String msg;
-			if (this.overrideRecipient != null)
-				msg = MessageFormat.format("Sent E-mail to override recipient {0}: {1}",
-						message.getRecipients(Message.RecipientType.TO)[0], message.getSubject());
-			else {
-				msg = MessageFormat.format("Sent E-mail to {0}: {1}",
-						message.getRecipients(Message.RecipientType.TO)[0], message.getSubject());
+					// override, with no white list, so send to override
+					text = "Override recipient. Original recipients: " + recipients + ".\n\n" + text;
+					send(subject, text, this.overrideRecipients);
+					logger.info(MessageFormat.format("Sent E-mail to override recipient {0}: {1}",
+							Arrays.asList(this.overrideRecipients).stream() //
+									.map(Object::toString) //
+									.collect(Collectors.joining(",")),
+							subject));
+				}
 			}
-			logger.info(msg);
 
 		} catch (MessagingException e) {
 			throw new RuntimeException("Failed to send e-mail due to " + e.getMessage(), e);
 		}
 	}
+
+	private void send(String subject, String text, InternetAddress[] recipients) throws MessagingException {
+
+		Session session = Session.getInstance(this.props, new javax.mail.Authenticator() {
+			protected PasswordAuthentication getPasswordAuthentication() {
+				return new PasswordAuthentication(SmtpMailer.this.username, SmtpMailer.this.password);
+			}
+		});
+
+		Message message = new MimeMessage(session);
+		message.setFrom(this.from);
+		message.addRecipients(Message.RecipientType.TO, recipients);
+		message.setSubject(subject);
+		message.setText(text);
+
+		Transport.send(message);
+	}
 }