13.x
[10.x] Adds inline attachments support for markdown mailables (#47140)
[10.x] Allow serialization of NotificationSent (#47375)
[12.x] Fix embedded image Content-ID inconsistency in cloned emails (#57726)
Fix: multi-line embedded image replacement in mail views (#56828)
[11.x] Fix `Illuminate\Support\EncodedHtmlString` from causing breaking change (#55149)
[11.x] Fix `EncodedHtmlString` to ignore instance of `HtmlString` (#55543)
Mailables can hook into LocaleUpdated
ability to set locale on sent Mailable
