diff --git a/NEWS b/NEWS
index bd0ddc144c..326290cbbc 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,7 @@ Bug fixes
  - [web] keep center list of Calendar module visible on small screens
  - [web] check for duplicate name only if address book name is changed
  - [web] improved detection of URLs and email addresses in text mail parts
+ - [web] fixed page reload with external IMAP account (#4709)
  - [core] allow super users to modify any event (#4216)
  - [core] correctly handle the full cert chain in S/MIME
  - [core] handle multidays events in freebusy data
diff --git a/UI/WebServerResources/js/Mailer/Account.service.js b/UI/WebServerResources/js/Mailer/Account.service.js
index 0638aa25a1..abbad4aabc 100644
--- a/UI/WebServerResources/js/Mailer/Account.service.js
+++ b/UI/WebServerResources/js/Mailer/Account.service.js
@@ -65,12 +65,17 @@
    * @returns the list of accounts
    */
   Account.$findAll = function(data) {
-    if (!data) {
+    if (data) {
+      return Account.$unwrapCollection(data);
+    }
+    else if (Account.$accounts) {
+      return Account.$q.when(Account.$accounts);
+    }
+    else {
       return Account.$$resource.fetch('', 'mailAccounts').then(function(o) {
         return Account.$unwrapCollection(o);
       });
     }
-    return Account.$unwrapCollection(data);
   };
 
   /**
@@ -133,8 +138,11 @@
     if (this.$mailboxes && !(options && options.reload)) {
       return Account.$q.when(this.$mailboxes);
     }
+    else if (this.$futureMailboxesData) {
+      return this.$futureMailboxesData;
+    }
     else {
-      return Account.$Mailbox.$find(this, options).then(function(data) {
+      this.$futureMailboxesData = Account.$Mailbox.$find(this, options).then(function(data) {
         _this.$mailboxes = data;
         _this.$expanded = false;
 
@@ -174,6 +182,7 @@
 
         return _this.$mailboxes;
       });
+      return this.$futureMailboxesData;
     }
   };
 
diff --git a/UI/WebServerResources/js/Mailer/Mailer.app.js b/UI/WebServerResources/js/Mailer/Mailer.app.js
index 2790ef600e..821b71eb62 100644
--- a/UI/WebServerResources/js/Mailer/Mailer.app.js
+++ b/UI/WebServerResources/js/Mailer/Mailer.app.js
@@ -211,16 +211,18 @@
     if (Mailbox.selectedFolder && !Mailbox.$virtualMode)
       Mailbox.selectedFolder.$isLoading = true;
 
-    mailbox = _find(stateAccount.$mailboxes);
-
-    if (mailbox) {
-      mailbox.$topIndex = 0;
-      mailbox.selectFolder();
-      return mailbox;
-    }
-    else
-      // Mailbox not found
-      return $q.reject("Mailbox doesn't exist");
+    return stateAccount.$getMailboxes().then(function (mailboxes) {
+      mailbox = _find(mailboxes);
+      if (mailbox) {
+        mailbox.$topIndex = 0;
+        mailbox.selectFolder();
+        return mailbox;
+      }
+      else {
+        // Mailbox not found
+        $state.go('mail.account', { accountId: stateMailbox.$account.id });
+      }
+    });
   }
 
   /**