diff --git a/ChangeLog b/ChangeLog
index 6975717..167e615 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2013-03-18: Niels Grewe <niels.grewe@halbordnung.de>
+	* EcAlerter.h
+	* EcAlerter.m:
+	Rearrange and expose a few methods so that subclasses can
+	easily inject alert rules.
+	* EcControl.m:
+	Allow dynamically loading the alerter class based on the
+	AlerterBundle key in AlertConfig.plist
+
 2013-03-18  Richard Frith-Macdonald <rfm@gnu.org>
 
 	* EcProcess.h:
diff --git a/EcAlerter.h b/EcAlerter.h
index 8413bf7..68c199a 100644
--- a/EcAlerter.h
+++ b/EcAlerter.h
@@ -49,6 +49,7 @@
   GSMimeSMTPClient	*smtp;
 }
 - (BOOL) configure: (NSNotification*)n;
+- (BOOL) configureWithDefaults: (NSDictionary*)c;
 - (void) handleInfo: (NSString*)str;
 - (void) flushEmail;
 - (void) flushSms;
@@ -56,5 +57,6 @@
 - (void) mail: (NSMutableDictionary*)m to: (NSArray*)destinations;
 - (void) sms: (NSMutableDictionary*)m to: (NSArray*)destinations;
 - (void) timeout: (NSTimer*)t;
+- (BOOL) setRules: (NSArray*)ra;
 @end
 
diff --git a/EcAlerter.m b/EcAlerter.m
index 57ae9b2..b61fafd 100644
--- a/EcAlerter.m
+++ b/EcAlerter.m
@@ -252,21 +252,28 @@ replaceFields(NSDictionary *fields)
 {
   NSUserDefaults	*d;
   NSDictionary		*c;
-  NSMutableArray	*r;
-  unsigned int		i;
 
   d = [EcProc cmdDefaults];
   c = [d dictionaryForKey: @"Alerter"];
+  return [self configureWithDefaults: c];
+}
 
+- (BOOL) configureWithDefaults: (NSDictionary*)c
+{
   ASSIGNCOPY(eHost, [c objectForKey: @"EmailHost"]);
   ASSIGNCOPY(eFrom, [c objectForKey: @"EmailFrom"]);
   ASSIGNCOPY(ePort, [c objectForKey: @"EmailPort"]);
+  return [self setRules: [c objectForKey: @"Rules"]];
+}
 
-  /*
-   * Cache a copy of the Rules with modifications to store information
-   * so we don't need to regenerate it every time we check a message.
-   */
-  r = [[[c objectForKey: @"Rules"] mutableCopy] autorelease];
+/*
+ * Cache a copy of the Rules with modifications to store information
+ * so we don't need to regenerate it every time we check a message.
+ */
+- (BOOL)setRules: (NSArray*)ra
+{
+  NSUInteger i = 0;
+  NSMutableArray *r = AUTORELEASE([ra mutableCopy]); 
   for (i = 0; i < [r count]; i++)
     {
       NSMutableDictionary	*md;
diff --git a/EcControl.m b/EcControl.m
index 2302d98..3d22b35 100644
--- a/EcControl.m
+++ b/EcControl.m
@@ -2345,6 +2345,40 @@ static NSString*	cmdWord(NSArray* a, unsigned int pos)
 	       from: nil];
 }
 
+
+- (Class)_loadClassFromBundle: (NSString*)bundleName
+{
+  NSString *path = nil;
+  Class c = Nil;
+  NSBundle *bundle = nil;
+  path = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory,
+    NSLocalDomainMask, YES) lastObject];
+  path = [path stringByAppendingPathComponent: @"Bundles"];
+  path = [path stringByAppendingPathComponent: bundleName];
+  path = [path stringByAppendingPathExtension: @"bundle"];
+  bundle = [NSBundle bundleWithPath: path];
+
+  if (nil == bundle)
+    {
+      [[self cmdLogFile: logname] printf: 
+       @"Couldn't load bundle '%@'", bundleName];
+    }
+  else if (Nil == (c = [bundle principalClass]))
+    {
+      [[self cmdLogFile: logname] printf: 
+        @"Couldn't load principal class from %@"
+        @" at %@.", bundleName, path];
+    }
+  else if (NO == [c isSubclassOfClass: [EcAlerter class]])
+    {
+      [[self cmdLogFile: logname] printf: 
+        @"%@ is not a subclass of EcAlerter", 
+        NSStringFromClass(c)];
+      c = Nil;
+    }
+  return c;
+}
+
 - (BOOL) update
 {
   NSMutableDictionary	*dict;
@@ -2358,6 +2392,7 @@ static NSString*	cmdWord(NSArray* a, unsigned int pos)
   unsigned		count;
   unsigned		i;
   BOOL			changed = NO;
+  Class			alerterClass = Nil;
 
   host = [NSHost currentHost];
   str = [NSHost controlWellKnownName];
@@ -2393,10 +2428,40 @@ static NSString*	cmdWord(NSArray* a, unsigned int pos)
             d, @"Alerter", nil];
           [[self cmdDefaults] setConfiguration: d];
           changed = YES;
+	 
         }
+      NSString *alerterDef = [[d objectForKey: @"Alerter"] 
+        objectForKey: @"AlerterBundle"];
+      if (nil == alerterDef)
+	{
+	  alerterClass = [EcAlerter class];
+	}
+      else
+	{
+	  // First, let's try whether this corresponds to
+	  // a class we already loaded.
+	  alerterClass = NSClassFromString(alerterDef);
+	  if (Nil == alerterClass)
+	    {
+	      // We didn't link the class. Try to load it 
+	      // from a bundle.
+	      alerterClass = 
+	        [self _loadClassFromBundle: alerterDef];
+	    }
+
+	}
+      if (Nil == alerterClass)
+	{
+	  NSLog(@"Could not load alerter class '%@'", alerterDef);
+	}
+      else if ([alerter class] != alerterClass)
+	{
+	  DESTROY(alerter);
+	}
+
       if (nil == alerter)
         {
-	  alerter = [EcAlerter new];
+	  alerter = [alerterClass new];
 	}
     }