[MlMt] Ignore or fix Runbox marking email as spam

[Ron Britton]

> You might want to take a look at Runbox's filtering options - see 
> https://help.runbox.com/filter/
>
> I use Runbox too and generally find their spam-filtering pretty good. 
> You can 'train' it to your specific needs using their webmail 
> interface. I don't think Mailmate has any direct influence on what 
> gets marked (or not) as spam by Runbox.

Thanks. I wasn’t clear on that. I think this will solve my problem.