Newline in To: field not handled

[MacGeyer]

Handling the following fails when using mini_sendmail but works fine when sending directly to Postfix
...
From: test x@xx.com
To: m <m.mmmmmmm@mmmmm.com>, r <r.rrrrr@rrrrr.com>, b
<b.bbbbbbbb@bbbbb.com>, w <w.wwwww@wwwww.com>
Subject: Message
...