Disclaimer: I am not yet familiar with the working of WMF mail ops, who's doing what. Feel free to share the info I may need to go on.
It is an ongoing problem that non-English OTRS languages that mail get higher scores than normal due to seemingly English based bayesian scoring. It is not a good direction IMNSHO that we try to hack this with OTRS filtering since it'd require the system to dissect the final score to its components or other horribilities. I do not see how much the incoming is common with other parts of WMF email but I suggest that OTRS should get a separate SA scoring, or at least a separate bayes db.
If that's the case (which I hope it is) then the bayesian db needs serious training with non-English non-spam email. I am obviously interested in Hungarian training but others mentioned that the problem is not unique to hu.
There is an OTRS Secret Agent™ only discussion embryo on https://otrs-wiki.wikimedia.org/wiki/Administrator_requests#OTRS_spam_filtering but it basically requires someone who's fiddling with the OTRS incoming MTA, the SA it uses and its config. (There were some smaller problems noticed in the scoring, too, or at least a few question risen.)
You may use my (limited) resources if you need it, I happen to administer mailservers for the last few decades along other things.