diff --git a/pom.xml b/pom.xml
index e5c43e1..17c8d80 100644
--- a/pom.xml
+++ b/pom.xml
@@ -57,6 +57,12 @@
             <version>1.10.19</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.codemonkey.simplejavamail</groupId>
+            <artifactId>simple-java-mail</artifactId>
+            <version>2.5.1</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
 </project>
diff --git a/src/main/java/net/kemitix/wiser/assertions/WiserAssertions.java b/src/main/java/net/kemitix/wiser/assertions/WiserAssertions.java
index a2fc2b6..07d0c56 100644
--- a/src/main/java/net/kemitix/wiser/assertions/WiserAssertions.java
+++ b/src/main/java/net/kemitix/wiser/assertions/WiserAssertions.java
@@ -269,7 +269,12 @@ public final class WiserAssertions {
             throws MessagingException, IOException {
         final StringBuilder sb = new StringBuilder();
         for (int i = 0; i < mimeMultipart.getCount(); i++) {
-            sb.append(mimeMultipart.getBodyPart(i).getContent());
+            Object content = mimeMultipart.getBodyPart(i).getContent();
+            if (content instanceof MimeMultipart) {
+                sb.append(getMimeMultipartAsString((MimeMultipart) content));
+            } else {
+                sb.append(content);
+            }
         }
         return sb.toString();
     }
diff --git a/src/test/java/net/kemitix/wiser/assertions/AbstractWiserTest.java b/src/test/java/net/kemitix/wiser/assertions/AbstractWiserTest.java
new file mode 100644
index 0000000..675bbfa
--- /dev/null
+++ b/src/test/java/net/kemitix/wiser/assertions/AbstractWiserTest.java
@@ -0,0 +1,64 @@
+package net.kemitix.wiser.assertions;
+
+import org.junit.After;
+import org.junit.Before;
+import org.subethamail.wiser.Wiser;
+
+import java.util.Properties;
+
+import javax.mail.Session;
+
+/**
+ * Abstract base class for wiser tests.
+ *
+ * @author pcampbell
+ */
+public abstract class AbstractWiserTest {
+
+    /**
+     * Test mail server port.
+     */
+    protected static final int PORT = 12345;
+
+    /**
+     * Test mail server.
+     */
+    private Wiser wiser;
+
+    /**
+     * Prepare each test.
+     */
+    @Before
+    @SuppressWarnings("magicnumber")
+    public void setUp() {
+        wiser = new Wiser(PORT);
+        wiser.start();
+    }
+
+    /**
+     * Clean up after each test.
+     */
+    @After
+    public void tearDown() {
+        wiser.stop();
+    }
+
+    /**
+     * Instantiates the WiserAssertions.
+     *
+     * @return the wiser assertions
+     */
+    protected WiserAssertions getAssertions() {
+        return WiserAssertions.assertReceivedMessage(wiser);
+    }
+
+    protected Session getSession() {
+        Properties properties = new Properties();
+        properties.setProperty("mail.transport.protocol", "smtp");
+        properties.setProperty("mail.smtp.host", "localhost");
+        properties.setProperty("mail.smtp.port", "" + WiserAssertionsTest.PORT);
+        Session session = Session.getDefaultInstance(properties);
+        return session;
+    }
+
+}
diff --git a/src/test/java/net/kemitix/wiser/assertions/Issue1Test.java b/src/test/java/net/kemitix/wiser/assertions/Issue1Test.java
new file mode 100644
index 0000000..76cc6bb
--- /dev/null
+++ b/src/test/java/net/kemitix/wiser/assertions/Issue1Test.java
@@ -0,0 +1,37 @@
+package net.kemitix.wiser.assertions;
+
+import org.codemonkey.simplejavamail.Email;
+import org.codemonkey.simplejavamail.Mailer;
+import org.junit.Test;
+
+import javax.mail.Message;
+
+/**
+ * Regression test for issue #1.
+ *
+ * @see https://github.com/kemitix/wiser-assertions/issues/1
+ * @author pcampbell
+ */
+public class Issue1Test extends AbstractWiserTest {
+
+    /**
+     * Test {@link WiserAssertions#withContentContains(String)} where the nested
+     * multi-part message contains the expected text.
+     */
+    @Test
+    public void shouldParseNestedMultiPartEmails() {
+        //given
+        final Email email = new Email();
+        email.addRecipient("Carl", "carl@b.com",
+                Message.RecipientType.TO);
+        email.setFromAddress("Bob", "bob@a.com");
+        email.setSubject("Subject");
+        email.setText("Hi Carl,\n\nA new message was just posted.");
+        Mailer mailer = new Mailer(getSession());
+        //when
+        mailer.sendMail(email);
+        //then
+        getAssertions().withContentContains("Hi Carl");
+    }
+
+}
diff --git a/src/test/java/net/kemitix/wiser/assertions/WiserAssertionsTest.java b/src/test/java/net/kemitix/wiser/assertions/WiserAssertionsTest.java
index ce9e22c..83d52f1 100644
--- a/src/test/java/net/kemitix/wiser/assertions/WiserAssertionsTest.java
+++ b/src/test/java/net/kemitix/wiser/assertions/WiserAssertionsTest.java
@@ -1,21 +1,17 @@
 package net.kemitix.wiser.assertions;
 
-import org.junit.After;
-import org.junit.Before;
 import org.junit.Test;
 import org.subethamail.wiser.Wiser;
 
 import static org.junit.Assert.assertNotNull;
 
 import java.io.IOException;
-import java.util.Properties;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import javax.mail.Message;
 import javax.mail.MessagingException;
 import javax.mail.Multipart;
-import javax.mail.Session;
 import javax.mail.Transport;
 import javax.mail.internet.InternetAddress;
 import javax.mail.internet.MimeBodyPart;
@@ -27,7 +23,7 @@ import javax.mail.internet.MimeMultipart;
  *
  * @author pcampbell
  */
-public class WiserAssertionsTest {
+public class WiserAssertionsTest extends AbstractWiserTest {
 
     /**
      * Logger.
@@ -35,34 +31,6 @@ public class WiserAssertionsTest {
     private static final Logger LOG
             = Logger.getLogger(WiserAssertionsTest.class.getName());
 
-    /**
-     * Test mail server.
-     */
-    private Wiser wiser;
-
-    /**
-     * Prepare each test.
-     */
-    @Before
-    @SuppressWarnings("magicnumber")
-    public void setUp() {
-        wiser = new Wiser(PORT);
-        wiser.start();
-    }
-
-    /**
-     * Test mail server port.
-     */
-    private static final int PORT = 12345;
-
-    /**
-     * Clean up after each test.
-     */
-    @After
-    public void tearDown() {
-        wiser.stop();
-    }
-
     /**
      * Sends a mime multipart message to the Wiser server.
      *
@@ -76,12 +44,8 @@ public class WiserAssertionsTest {
             final String to,
             final String subject,
             final String body) {
-        Properties properties = new Properties();
-        properties.setProperty("mail.smtp.host", "localhost");
-        properties.setProperty("mail.smtp.port", "" + PORT);
-        Session session = Session.getDefaultInstance(properties);
         try {
-            MimeMessage message = new MimeMessage(session);
+            MimeMessage message = new MimeMessage(getSession());
             message.setFrom(new InternetAddress(from));
             message.setRecipients(Message.RecipientType.TO, to);
             message.setSubject(subject, "UTF-8");
@@ -96,15 +60,6 @@ public class WiserAssertionsTest {
         }
     }
 
-    /**
-     * Instantiates the WiserAssertions.
-     *
-     * @return the wiser assertions
-     */
-    private WiserAssertions getAssertions() {
-        return WiserAssertions.assertReceivedMessage(wiser);
-    }
-
     /**
      * Test {@link WiserAssertions#withContent(java.lang.String)} where the
      * content of the email matches.