diff --git a/app/Maildispatcher/Actions/ResyncAction.php b/app/Maildispatcher/Actions/ResyncAction.php
index 671d2434..57f1dce0 100644
--- a/app/Maildispatcher/Actions/ResyncAction.php
+++ b/app/Maildispatcher/Actions/ResyncAction.php
@@ -27,6 +27,9 @@ class ResyncAction
     {
         return Member::search(data_get($dispatcher->filter, 'search', ''))->query(
             fn ($q) => $q->select('*')->withFilter(FilterScope::fromPost($dispatcher->filter))
-        )->get()->filter(fn ($member) => $member->email || $member->email_parents)->map(fn ($member) => MailEntry::from(['email' => $member->email ?: $member->email_parents]));
+        )->get()
+            ->filter(fn ($member) => $member->email || $member->email_parents)
+            ->map(fn ($member) => MailEntry::from(['email' => $member->email ?: $member->email_parents]))
+            ->unique(fn ($member) => $member->email);
     }
 }
diff --git a/tests/Feature/Maildispatcher/StoreTest.php b/tests/Feature/Maildispatcher/StoreTest.php
index 47b850be..b6490f2c 100644
--- a/tests/Feature/Maildispatcher/StoreTest.php
+++ b/tests/Feature/Maildispatcher/StoreTest.php
@@ -2,6 +2,7 @@
 
 namespace Tests\Feature\Maildispatcher;
 
+use \Mockery as M;
 use App\Activity;
 use App\Maildispatcher\Models\Localmaildispatcher;
 use App\Maildispatcher\Models\Maildispatcher;
@@ -50,6 +51,23 @@ class StoreTest extends TestCase
         ]);
     }
 
+    public function testItDoesntStoreTwoMembersWithSameEmailAddress(): void
+    {
+        $type = M::mock(LocalType::class)->makePartial();
+        $type->shouldReceive('add')->once();
+        app()->instance(LocalType::class, $type);
+
+        $gateway = Mailgateway::factory()->type(LocalType::class, [])->domain('example.com')->create();
+        Member::factory()->defaults()->create(['email' => 'jane@example.com']);
+        Member::factory()->defaults()->create(['email' => 'jane@example.com']);
+
+        $this->postJson('/maildispatcher', [
+            'name' => 'test',
+            'gateway_id' => $gateway->id,
+            'filter' => [],
+        ]);
+    }
+
     public function testMaildispatcherReceivesLowerVersionOfEmail(): void
     {
         $gateway = Mailgateway::factory()->type(LocalType::class, [])->create();