Missing Normalization in Rules

I have several participants in rule lists, who write their email address differently from time to time, although being the same address. The difference lies in using capital letters or not. The emClient obviously sees a difference if capital letters are used. That’s wrong.

There is no capitalization taken into account with email addresses.

So a Rule that is looking for forum@eMCLient.com will also apply to messages from forUM@emclienT.com

But I have some duplicates in the rule’s list and had to do the ‘apply’ twice, to get all items.