On Sun, Feb 23, 2020 at 01:23:11PM +0200, Dimitris wrote:
> On 2/23/20 1:03 PM, Mark Hindley wrote:
> > Just writing an email? Which client?
>
> just a single email through thunderbird mua (ceres latest), to
> submit@??? , with a subject & pseudoheader as per
> instructions here : https://bugs.devuan.org/Reporting.html

OK, I think I have identified the problem (if not a fix, yet).

You appear to be using the Thunderbird Autocrypt addon. This is adding a
duplicate To: header to your email. And that means the email is handled twice by
debbugs.

Mark