mbox takes any sentence starting by `^From ` as a new message

The mbox backend parses anything starting with `From` as a new message. Therefore, the following message from OpenStack will be taken as 2 messages:

```
From eric at cloudscaling.com Thu Aug 9 18:39:17 2012
From: eric at cloudscaling.com (Eric Windisch)
Date: Thu, 9 Aug 2012 14:39:17 -0400
Subject: [openstack-dev] [Openstack] Making the RPC backend a required
configuration parameter
In-Reply-To: <5023F1C7.90205@redhat.com>
References: <606206A0BADB4E13BABB52D7E06E7804@cloudscaling.com>
<5023F1C7.90205@redhat.com>
Message-ID:

>
> I also don't understand why having a default that doesn't work for
> anyone makes any sense.
>
I would hope that a localhost only installation with a username and password of 'guest' include a very small number of anyones. Who is really using a completely stock, default configuration successfully, and do they really care? Everyone else is using configuration management of sorts, at which point this discussion is moot. Even devstack changes this configuration.

If someone really is installing Nova from scratch and using a default configuration? Does setuptools also install RabbitMQ for you? No? Right, you need to read documentation and recognize that RabbitMQ needs to be installed. Sure, once it is installed, no configuration is required; Unless you're /actually/ going to use it, of course.

From everything I've seen, the general recommendation on the mailing list for those installing Nova on a single node is to use devstack. In that case, the configuration is prompt-driven, and whatever changes need to be made, can be made.

Regards,
Eric Windisch

```

The main issue is that leaves the message truncated. In this example, the last paragraph and signature will be lost.

If the purpose is to only parse metadata, the approach is ok. Although there would not be reason to store the body of the message.

Start by locating the mbox backend and reproduce the supplied OpenStack message to confirm how the second `From` line is treated. Done means the message is no longer split incorrectly and the final paragraph and signature are preserved; the issue does not name a specific file or test to run.

Written by the indexing model from the issue text.