diff --git a/migrations/042-add-site-is-notified-field.js b/migrations/042-add-site-is-notified-field.js
new file mode 100755
index 00000000..fa2b3f76
--- /dev/null
+++ b/migrations/042-add-site-is-notified-field.js
@@ -0,0 +1,15 @@
+let db = require('../src/db').sequelize;
+
+module.exports = {
+  up: function() {
+
+    try {
+      return db.query(`
+        ALTER TABLE sites ADD adminIsNotified DATETIME NULL DEFAULT NULL AFTER areaId; 
+			`);
+    } catch(e) {
+      return true;
+    }
+
+  }
+}
diff --git a/src/cron/send_site_issues_notifications.js b/src/cron/send_site_issues_notifications.js
index b72df737..b05759e9 100755
--- a/src/cron/send_site_issues_notifications.js
+++ b/src/cron/send_site_issues_notifications.js
@@ -31,8 +31,10 @@ module.exports = {
         // for each site
         for (let i=0; i < shouldHaveEndedButAreNot.length; i++) {
           let site = shouldHaveEndedButAreNot[i];
-          if (!notificationsToBeSent[ site.id ]) notificationsToBeSent[ site.id ] = { site, messages: [] };
-          notificationsToBeSent[ site.id ].messages.push(`Site ${ site.title } (${ site.domain }) has an endDate in the past but projectHasEnded is not set.`);
+          if (!site.adminIsNotified || site.adminIsNotified.getTime() < Date.now() - 23 * 60 * 60 * 1000) {
+            if (!notificationsToBeSent[ site.id ]) notificationsToBeSent[ site.id ] = { site, messages: [] };
+            notificationsToBeSent[ site.id ].messages.push(`Site ${ site.title } (${ site.domain }) has an endDate in the past but projectHasEnded is not set.`);
+          }
         }
 
         // sites that have ended but are not anonymized
@@ -42,22 +44,38 @@ module.exports = {
         // for each site
         for (let i=0; i < endedButNotAnonymized.length; i++) {
           let site = endedButNotAnonymized[i];
-          if (!notificationsToBeSent[ site.id ]) notificationsToBeSent[ site.id ] = { site, messages: [] };
-          notificationsToBeSent[ site.id ].messages.push(`Project ${ site.title } (${ site.domain }) has ended but is not yet anonymized.`);
+          if (!site.adminIsNotified || site.adminIsNotified.getTime() < Date.now() - 23 * 60 * 60 * 1000) {
+            if (!notificationsToBeSent[ site.id ]) notificationsToBeSent[ site.id ] = { site, messages: [] };
+            notificationsToBeSent[ site.id ].messages.push(`Project ${ site.title } (${ site.domain }) has ended but is not yet anonymized.`);
+          }
         }
 
-        // send notifications
+        // aggregate notifications to the same address
+        let aggregatedNotificationsToBeSent = [];
         Object.keys(notificationsToBeSent).forEach(id => {
           let target = notificationsToBeSent[ id ];
-          let data = {
-            from: target.site.config.notifications.fromAddress,
-            to: target.site.config.notifications.siteadminAddress,
-            subject: 'Sites with issues',
-            template: target.messages.join('\r\n'),
-          };
-          Notifications.sendMessage({ site: target.site, data });
+          let toAddress = target.site.config.notifications.siteadminAddress || target.site.config.notifications.projectmanagerAddress;
+          if ( aggregatedNotificationsToBeSent[ toAddress ] ) {
+            aggregatedNotificationsToBeSent[ toAddress ].data.template += '<br/>\r\n' + target.messages.join('<br/>\r\n');
+          } else {
+            aggregatedNotificationsToBeSent[ toAddress ] = {
+              site: target.site,
+              data: {
+                from: target.site.config.notifications.fromAddress,
+                to: toAddress,
+                subject: 'Sites with issues',
+                template: target.messages.join('<br/>\r\n'),
+              }
+            };
+          }
+          target.site.update({ adminIsNotified: new Date() })
         });
-        
+
+        // send notifications
+        Object.values(aggregatedNotificationsToBeSent).forEach(target => {
+          Notifications.sendMessage({ site: target.site, data: target.data });
+        })
+
         return next();
 
       } catch (err) {
diff --git a/src/models/Site.js b/src/models/Site.js
index f9cfb8e0..d8245fb3 100755
--- a/src/models/Site.js
+++ b/src/models/Site.js
@@ -67,7 +67,13 @@ module.exports = function (db, sequelize, DataTypes) {
     areaId: {
       type: DataTypes.INTEGER,
       allowNull: true,
-    }
+    },
+
+    adminIsNotified: {
+      type: DataTypes.DATE,
+      allowNull: true,
+      default: null,
+    },
 
   }, {