It seems no related posts appear at all now.
Note that my site is part of a WordPress multisite installation.
The url is http://www.reflektis.com/blog-en for the blog articles that I want to show related posts.
That is strange, since disabling Rootspersona “frees” the wp_mail function.
No idea what to do now to use both Rootspersona and wpMandrill…
The error I get is:
“Mandrill: wp_mail has been declared by another process or plugin, so you won’t be able to use Mandrill until the problem is solved.”
I narrowed the problem down to Rootspersona, by disabling all plugins and enabling them one by one.
that is weird, I tried various things, implemented the buttons by hand and disabled the Jetpack Publicize.
At your question I re-enabled the Jetpack and it works great now! I have no explanation, but thanks anyway.
Sorry. Removed them because they did not work and manually added my own.
I re-enabled them now.