Hi Peter,

On 05.04.2020 10:03, Peter Müller wrote:
>...
> In that particular case, however, your message probably contained a link to
> libpng[.]org, which resolves to 216.105.38.10, which has been blacklisted due
> to malware distribution at 2019-06-15.
> ...

ARGL! I thought about something like that, but didn't check closely
enough. *sigh*

I'll try again with a modified URL.

Thanks for looking at this!

Best,
Matthias