Simple email forward route

Hi all,
I'm going to post a question that has already been posted here
<http://camel.465427.n5.nabble.com/Forward-mail-via-camel-td5715953.html>
and here
<http://camel.465427.n5.nabble.com/Missing-start-boundary-exception-on-camel-mail-2-10-2-td5724769.html>
, without resolution. Since the previous posts are 1 or 2 years old, I
thought the better thing was to make a new post. We can then point those
posts to here if we get a solution.

Said that, I'm trying to implement a complex route that involves reading and
writing emails, but I'm getting consistently a "Missing start boundary"
exception for which I'm asking for help here. After stripping out from the
route everything not related to the exception, I ended up with this simple
spring route:

<route>
<from
uri="imap://mailserver:143?username=receiver [ at ] foodomain.com橪;password=xxxxxx橪;consumer.delay=1000"/>
<setHeader
headerName="from"><constant>receiver [ at ] foodomain.com</constant></setHeader>
<setHeader
headerName="to"><constant>forwardto [ at ] foodomain.com</constant></setHeader>
<to uri="smtp://mailserver:225"/>
</route>

My camel version is 2.14.0, java is 1.7.
Here is the email writeTo format, as taken from
MimeMultipart.writeTo(FileOutputStream): emailWriteTo.txt
<http://camel.465427.n5.nabble.com/file/n5759253/emailWriteTo.txt>
Here is the stacktrace of the error: Stacktrace02.txt
<http://camel.465427.n5.nabble.com/file/n5759253/Stacktrace02.txt>

What is causing the exception?
Let me know if there's anything else I can provide to help identify the
problem which most surely is somewhere in my configuration.

Thanks for any suggestion,
A.