Fix contacts unsubscribed from oldest mailing list

Fixes #538

Author: bencroker

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## 3.7.3 - Unreleased
 
 - Removed the requirement for edit permission to the primary site to edit contacts ([#532](https://github.com/putyourlightson/craft-campaign/issues/532)).
+- Fixed a bug in which contacts were being unsubscribed from the oldest mailing list they were subscribed to, regardless of whether it was included in the sendout ([#538](https://github.com/putyourlightson/craft-campaign/issues/538)).
 
 ## 3.7.2 - 2025-11-25
 

src/services/SendoutsService.php

@@ -654,6 +654,7 @@ private function getPendingRecipientsStandard(SendoutElement $sendout, int $limi
             ->groupBy(['contactId'])
             ->andWhere([
                 'contactId' => $contactIds,
+                'mailingListId' => $sendout->mailingListIds,
                 'subscriptionStatus' => 'subscribed',
             ])
             ->orderBy(['contactId' => SORT_ASC])