diff --git a/addons/snailmail/static/src/js/message.js b/addons/snailmail/static/src/js/message.js
index b7b74e9242f..5549fe14261 100644
--- a/addons/snailmail/static/src/js/message.js
+++ b/addons/snailmail/static/src/js/message.js
@@ -21,7 +21,7 @@ Message.include({
         return this._rpc({
             model: 'mail.message',
             method: 'cancel_letter',
-            args: [[this.getID()], []],
+            args: [[this.getID()]],
         }).then(function () {
             self.setSnailmailStatus('canceled');
             self.setSnailmailError(false);
@@ -51,7 +51,7 @@ Message.include({
         return this._rpc({
             model: 'mail.message',
             method: 'send_letter',
-            args: [[this.getID()], []],
+            args: [[this.getID()]],
         });
     },
     /**
diff --git a/addons/snailmail/static/src/js/thread_widget.js b/addons/snailmail/static/src/js/thread_widget.js
index 4fd2521b4c7..84cc2a3b2dc 100644
--- a/addons/snailmail/static/src/js/thread_widget.js
+++ b/addons/snailmail/static/src/js/thread_widget.js
@@ -137,7 +137,7 @@ ThreadWidget.include({
             var content = _.str.sprintf(_t(
                 '<p>The letter could not be sent due to insufficient credits on your IAP account.</p>' +
                 '<div class= "text-right">' +
-                '<a class="btn btn-link buy_credits" href=%s>' +
+                '<a class="btn btn-link buy_credits" href=%s target="_blank">' +
                 '<i class= "fa fa-arrow-right"/> Buy credits' +
                 '</a>' +
                 '</div>'