I just want to let you know that in more formal way

Please be advised that...
Keep in mind that...
Thanks

I would like to inform you that .....

In spoken English, one jumps to the point with these generic phrases because the pause after 'that' works as intonation with the actual emphasis on the idea 'Be attentive to what your about to hear.' You can communicate what you think is important to share next using an unbroken melody. It's sort of a pre-made response to the request: Please advise me when, for instance, I am running out of time.

Usually, too: I just want to let you know how much, for instance, I like you. Compare: I just want to like you know that there's gum under that table. Thanks

Hi,

It depends whom and what you want to address to. So, 'I want to inform you...' should be more formal.

Regards

Reaz

I just want to let you know that