I saw this mod on a list, but the only link it has is from elricm.com. But when I click in it or go to the downloads section in elricm.com, it says "Session initialisation failed". Do you know any other site to download it? I've searched on tesnexus and PES for mournhold and didn't find it...

ElricM has the flu it seems.
It is always worth checking MMH.
Or here: http://www.mediafire.com/file/cru1at18qck6ffe/MournholdMagesGuild10CleanFinal.zip

Enjoy!