eM Client forum messages ending up in Junk E-Mail folder

Every day I receive eM Client forum messages in email (a POP3 account). I have an inbox rule that moves the forum messages from “Inbox” to a dedicated “eM Client” mail folder. Just within the last three or so days, a lot of the forum messages (but not all) have been sent automatically into the mail client’s “Junk E-Mail” folder instead.

(I am still using version 7.0.27943.0.)

I use Spam Arrest as my mail server. If Spam Arrest thinks that an incoming message is spam, it moves the message from its own inbox into a separate folder — and therefore I never receive such messages locally. So what might be in the daily eM Client forum emails that would suddenly cause them to be sent to “Junk E-Mail,” and how can I stop it from happening?

I haven’t changed the inbox rule for this, either. It’s the same as always.