diff --git a/src/Model/Filter.php b/src/Model/Filter.php
index 75d036f..424b7ee 100644
--- a/src/Model/Filter.php
+++ b/src/Model/Filter.php
@@ -48,9 +48,11 @@ class Filter
      */
     public function from($values)
     {
-        $this->properties['from'] = collect($values)->map(function ($value) {
-            return trim($value);
-        })->all();
+        if (!empty($values)) {
+            $this->properties['from'] = collect($values)->map(function ($value) {
+                return trim($value);
+            })->all();
+        }
 
         return $this;
     }
@@ -62,9 +64,11 @@ class Filter
      */
     public function to($values)
     {
-        $this->properties['to'] = collect($values)->map(function ($value) {
-            return trim($value);
-        })->all();
+        if (!empty($values)) {
+            $this->properties['to'] = collect($values)->map(function ($value) {
+                return trim($value);
+            })->all();
+        }
 
         return $this;
     }
diff --git a/tests/Unit/FilterTest.php b/tests/Unit/FilterTest.php
index aaded0c..ca3c3c1 100644
--- a/tests/Unit/FilterTest.php
+++ b/tests/Unit/FilterTest.php
@@ -58,6 +58,18 @@ class FilterTest extends TestCase
             ['from' => ['foo@example.com', 'bar@example.com']],
             $this->filter->from(['foo@example.com', 'bar@example.com'])->getProperties()
         );
+
+    }
+
+    /**
+     * Test that no 'from' key exists if no values were entered.
+     *
+     * @covers Filter::from()
+     */
+    public function testNoFromPropertyExistsIfTheValueIsEmpty()
+    {
+        $this->assertArrayNotHasKey('from', $this->filter->from('')->getProperties());
+        $this->assertArrayNotHasKey('from', $this->filter->from([])->getProperties());
     }
 
     /**
@@ -76,6 +88,15 @@ class FilterTest extends TestCase
         );
     }
 
+    /**
+     * Test that no 'to' key exists if values were entered.
+     */
+    public function testNoToPropertyExistsIfTheValueIsEmpty()
+    {
+        $this->assertArrayNotHasKey('to', $this->filter->to('')->getProperties());
+        $this->assertArrayNotHasKey('to', $this->filter->to([])->getProperties());
+    }
+
     /**
      * @covers Filter::subject()
      */