Maximum contacts for a message rule?

I have a rule set up that applies to 92 recipients. However only about 10 recipients get the rule applied to regularly. Is there a maximum limit to the number of contacts that can be applied in a rule? If not, what might cause this?

Hello Eric,
there is definitely no rule limit set up. Can you please describe how the rule is set up?
Does it perhaps only happen when you check the messages first on another device and only then in eM Client and the rule can no longer be applied because the message is not in inbox?

Regards,
Olivia

The message is definitely in the INBOX. However, I am having some contact syncing problems (which I have just posted as another question), so let me resolve that first.