diff --git a/hsarback/src/de/hsadmin/mods/email/EMailAlias.java b/hsarback/src/de/hsadmin/mods/email/EMailAlias.java
index ba274c3..f7c3fef 100644
--- a/hsarback/src/de/hsadmin/mods/email/EMailAlias.java
+++ b/hsarback/src/de/hsadmin/mods/email/EMailAlias.java
@@ -48,7 +48,7 @@ public class EMailAlias extends AbstractEntity implements Serializable {
 	@AnnFieldIO(validation="[a-z0-9]*", rw=ReadWriteAccess.READONLY)
 	private Pac pac;
 
-	@AnnFieldIO(validation="[a-z0-9]{5}(-[a-z0-9\\.\\_]{1,})?", rw=ReadWriteAccess.WRITEONCE)
+	@AnnFieldIO(validation="[a-z0-9]{5}(-[a-z0-9\\.\\_\\-]{1,})?", rw=ReadWriteAccess.WRITEONCE)
 	@Column(updatable=false)
 	private String name;
 
diff --git a/hsarback/test/de/hsadmin/validate/EMailAliasValidationTest.java b/hsarback/test/de/hsadmin/validate/EMailAliasValidationTest.java
new file mode 100644
index 0000000..34489e0
--- /dev/null
+++ b/hsarback/test/de/hsadmin/validate/EMailAliasValidationTest.java
@@ -0,0 +1,32 @@
+package de.hsadmin.validate;
+
+import java.util.regex.Pattern;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+public class EMailAliasValidationTest {
+
+	private Pattern pattern;
+
+	@Before
+	public void setUp() throws Exception {
+		pattern = Pattern.compile("[a-z0-9]{5}(-[a-z0-9\\.\\_\\-]{1,})?");
+	}
+
+	@Test
+	public void test() {
+		Assert.assertTrue("xyz00-a.b", pattern.matcher("xyz00-a.b").matches());
+		Assert.assertTrue("xyz00-a-b", pattern.matcher("xyz00-a-b").matches());
+		Assert.assertTrue("xyz00--b", pattern.matcher("xyz00-a-b").matches());
+		Assert.assertTrue("xyz00-a-", pattern.matcher("xyz00-a-b").matches());
+		Assert.assertFalse("xyz00-a.B", pattern.matcher("xyz00-a.B").matches());
+		Assert.assertFalse("xyz00-", pattern.matcher("xyz00-").matches());
+		Assert.assertTrue("xyz00", pattern.matcher("xyz00").matches());
+		Assert.assertFalse("xyz0", pattern.matcher("xyz0").matches());
+		Assert.assertFalse("xyz00_a", pattern.matcher("xyz00_a").matches());
+		Assert.assertFalse("xyz00-a.b:c", pattern.matcher("xyz00-a.b:c").matches());
+	}
+
+}