Error in user YAML: (<unknown>): found character that cannot start any token while scanning for the next token at line 5 column 16

---
title: Fix send mail message encoding
issue: NEXT-25651
author: Oliver Skroblin
author_email: o.skroblin@shopware.com
author_github: @OliverSkroblin
---

Core

Added SendEmailMessageJsonSerializer serializer which fixes the json encoding of the SendMailMessage class.