diff --git a/NEWS b/NEWS
index d550f2352..6f4ca0cc5 100644
--- a/NEWS
+++ b/NEWS
@@ -21,6 +21,7 @@ Bug fixes
  - [web] fixed responsive condition of login page (960px to 1023px)
  - [core] newly subscribed calendars are excluded from freebusy (#3354)
  - [core] strip cr during LDIF import process (#4172)
+ - [core] email alarms are sent too many times (#4100)
 
 3.2.9 (2017-05-09)
 ------------------
diff --git a/SoObjects/Appointments/iCalAlarm+SOGo.h b/SoObjects/Appointments/iCalAlarm+SOGo.h
index 741be01fa..6a7b84fb6 100644
--- a/SoObjects/Appointments/iCalAlarm+SOGo.h
+++ b/SoObjects/Appointments/iCalAlarm+SOGo.h
@@ -1,6 +1,6 @@
 /* iCalAlarm+SOGo.h - this file is part of SOGo
  *
- * Copyright (C) 2015 Inverse inc.
+ * Copyright (C) 2015-2017 Inverse inc.
  *
  * This file is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -21,6 +21,7 @@
 #import <NGCards/iCalAlarm.h>
 
 @class iCalEntityObject;
+@class SOGoUser;
 
 @interface iCalAlarm (SOGoExtensions)
 
@@ -34,4 +35,6 @@
       emailAttendees: (BOOL) reminderEmailAttendees
       emailOrganizer: (BOOL) reminderEmailOrganizer;
 
+- (BOOL) userIsAttendee: (SOGoUser *) user;
+
 @end
diff --git a/SoObjects/Appointments/iCalAlarm+SOGo.m b/SoObjects/Appointments/iCalAlarm+SOGo.m
index 4f98fc5eb..51e0d8a75 100644
--- a/SoObjects/Appointments/iCalAlarm+SOGo.m
+++ b/SoObjects/Appointments/iCalAlarm+SOGo.m
@@ -1,6 +1,6 @@
 /* iCalAlarm+SOGo.m - this file is part of SOGo
  *
- * Copyright (C) 2015 Inverse inc.
+ * Copyright (C) 2015-2017 Inverse inc.
  *
  * This file is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -125,4 +125,24 @@
   return AUTORELEASE(anAlarm);
 }
 
+- (BOOL) userIsAttendee: (SOGoUser *) user
+{
+  NSEnumerator *attendees;
+  iCalPerson *currentAttendee;
+  BOOL isAttendee;
+
+  isAttendee = NO;
+
+  attendees = [[self attendees] objectEnumerator];
+  currentAttendee = [attendees nextObject];
+  while (!isAttendee
+	 && currentAttendee)
+    if ([user hasEmail: [currentAttendee rfc822Email]])
+      isAttendee = YES;
+    else
+      currentAttendee = [attendees nextObject];
+
+  return isAttendee;
+}
+
 @end
diff --git a/SoObjects/Appointments/iCalEntityObject+SOGo.m b/SoObjects/Appointments/iCalEntityObject+SOGo.m
index 3db197ee0..679eb59b1 100644
--- a/SoObjects/Appointments/iCalEntityObject+SOGo.m
+++ b/SoObjects/Appointments/iCalEntityObject+SOGo.m
@@ -690,6 +690,7 @@ NSNumber *iCalDistantFutureNumber = nil;
 {
   NSCalendarDate *nextAlarmDate;
   GCSAlarmsFolder *af;
+  SOGoUser *alarmOwner;
   NSString *path;
 
   int email_alarm_number;
@@ -698,11 +699,13 @@ NSNumber *iCalDistantFutureNumber = nil;
     {
       af = [[GCSFolderManager defaultFolderManager] alarmsFolder];
       path = [theContainer ocsPath];
+      alarmOwner = [SOGoUser userWithLogin: [[path componentsSeparatedByString: @"/"] objectAtIndex: 2]];
     }
   else
     {
       af = nil;
       path = nil;
+      alarmOwner = nil;
     }
 
   nextAlarmDate = nil;
@@ -736,7 +739,8 @@ NSNumber *iCalDistantFutureNumber = nil;
 	      email_alarm_number = [[self alarms] indexOfObject: anAlarm];
 
 	      // The email alarm is too old, let's just remove it
-	      if ([nextAlarmDate earlierDate: [NSDate date]] == nextAlarmDate)
+	      if ([nextAlarmDate earlierDate: [NSDate date]] == nextAlarmDate ||
+                  ![anAlarm userIsAttendee: alarmOwner])
 		nextAlarmDate = nil;
 	      else
 		{
@@ -831,17 +835,21 @@ NSNumber *iCalDistantFutureNumber = nil;
                               nextAlarmDate = [NSDate dateWithTimeIntervalSince1970: [[[alarms objectAtIndex: i] objectForKey: @"c_nextalarm"] intValue]];
                             }
 			  else if ((anAlarm = [self firstEmailAlarm]) && af)
+
 			    {
 			      nextAlarmDate = [NSDate dateWithTimeIntervalSince1970: [[[alarms objectAtIndex: i] objectForKey: @"c_nextalarm"] intValue]];
 			      email_alarm_number = [[self alarms] indexOfObject: anAlarm];
 
-			      [af writeRecordForEntryWithCName: nameInContainer
-					      inCalendarAtPath: path
-							forUID: [self uid]
-						  recurrenceId: [self recurrenceId]
-						   alarmNumber: [NSNumber numberWithInt: email_alarm_number]
-						  andAlarmDate: nextAlarmDate];
-			    }
+                              if ([anAlarm userIsAttendee: alarmOwner])
+                                [af writeRecordForEntryWithCName: nameInContainer
+                                                inCalendarAtPath: path
+                                                          forUID: [self uid]
+                                                    recurrenceId: [self recurrenceId]
+                                                     alarmNumber: [NSNumber numberWithInt: email_alarm_number]
+                                                    andAlarmDate: nextAlarmDate];
+                              else
+                                nextAlarmDate = nil;
+                            }
 			}
                     }
                 } // for ( ... )
diff --git a/Tools/SOGoEAlarmsNotifier.m b/Tools/SOGoEAlarmsNotifier.m
index 5999d11c4..2a2a49dcf 100644
--- a/Tools/SOGoEAlarmsNotifier.m
+++ b/Tools/SOGoEAlarmsNotifier.m
@@ -124,28 +124,22 @@
 
 - (void) _sendMessageWithHeaders: (NGMutableHashMap *) headers
                          content: (NSData *) content
-                      toAttendee: (iCalPerson *) attendee
-                            from: (NSString *) from
+                              to: (NSDictionary *) to
                       withMailer: (SOGoMailer *) mailer
 {
   NGMimeMessage *message;
-  NSString *to, *headerTo, *attendeeName;
+  NSString *headerTo;
 
-  attendeeName = [attendee cnWithoutQuotes];
-  if ([attendeeName length])
-    headerTo = [NSString stringWithFormat: @"%@ <%@>", attendeeName,
-                         [attendee rfc822Email]];
-  else
-    headerTo = [attendee rfc822Email];
+  headerTo = [NSString stringWithFormat: @"%@ <%@>", [to objectForKey: @"fullName"],
+                       [to objectForKey: @"email"]];
   [headers setObject: headerTo forKey: @"To"];
   [headers setObject: [self _messageID] forKey: @"Message-Id"];
   message = [NGMimeMessage messageWithHeader: headers];
   [message setBody: content];
-  to = [attendee rfc822Email];
 
   [mailer sendMimePart: message
-          toRecipients: [NSArray arrayWithObject: to]
-                sender: from
+          toRecipients: [NSArray arrayWithObject: [to objectForKey: @"email"]]
+                sender: [to objectForKey: @"email"]
      withAuthenticator: staticAuthenticator inContext: nil];
 }
 
@@ -154,11 +148,10 @@
       andContainerPath: (NSString *) containerPath
 {
   NGMutableHashMap *headers;
-  NSArray *attendees, *parts;
+  NSArray *parts;
   NSData *content, *qpContent;
-  int count, max;
   SOGoMailer *mailer;
-  NSString *from, *subject;
+  NSString *subject;
   SOGoUser *owner;
 
   WOContext *localContext;
@@ -171,7 +164,6 @@
   SOGoAppointmentFolder *folder;
   SOGoUserFolder *userFolder;
 
-
   owner = [SOGoUser userWithLogin: ownerId];
   mailer = [SOGoMailer mailerWithDomainDefaults: [owner domainDefaults]];
 
@@ -180,13 +172,13 @@
   app = [[WOApplication alloc] initWithName: @"SOGo"];
 
   rm = [[WEResourceManager alloc] init];
-  [app setResourceManager:rm];
+  [app setResourceManager: rm];
   [rm release];
   [app _setCurrentContext:localContext];
 
   userFolder = [[localContext activeUser] homeFolderInContext: localContext ];
   folders = [userFolder privateCalendars: @"Calendar"
-                         inContext: localContext];
+                               inContext: localContext];
 
   pageName = [NSString stringWithFormat: @"SOGoAptMail%@", @"Reminder"];
 
@@ -209,16 +201,10 @@
 
   headers = [self _headersForAlarm: alarm withOwner: owner withSubject: subject];
   qpContent = [content dataByEncodingQuotedPrintable];
-  from = [[owner primaryIdentity] objectForKey: @"email"];
-
-  attendees = [alarm attendees];
-  max = [attendees count];
-  for (count = 0; count < max; count++)
-    [self _sendMessageWithHeaders: headers
-                          content: qpContent
-                       toAttendee: [attendees objectAtIndex: count]
-                             from: from
-                       withMailer: mailer];
+  [self _sendMessageWithHeaders: headers
+                        content: qpContent
+                             to: [owner primaryIdentity]
+                     withMailer: mailer];
 }
 
 - (void) usage