* Bernhard Reiter: " [issue2550869] Duplicate mail headers (Reply-To,
  Message-ID, In-Reply-To) when sending out email." (Thu, 19 Feb 2015 14:33:10
  +0000):

Hi Bernhard,

> thanks for the report and the suggested fix.
> I checked out one of our roundup emails and it had the doubled headers.
> So I consider the problem confirmed.
> 
> However before removing the lines like you have done in your patch,
> I think I must find out why they are there in the first place?
> There must be a situation where they where necessary, maybe with an 
> elder email python module or a different change elsewhere.

That was exactly my thought, too. I just couldn't find out, if there are
special cases where those headers need ot be (re)set. At least we are running
our roundup without the lines in question. In case they should be needed by some
legacy module and the lines should be considered necessary, at least there could
be a added a test to not add them twice.

Cheers,
Mathias
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    Mathias Behrle
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