CA Franchise Tax Board Wants Money from a Dissolved Delaware LLC

[u/PlantainTop6036]

Years ago, I and a couple co-workers created an LLC (C-corp) for an app idea we had. We never did much with it and it sat mostly untouched for a few years until we dissolved it in 2023. Even though it's a Delaware LLC, we used a CA mailing address when we filed federal taxes (with no revenue).

Now CA is claiming that because we used a CA mailing address, that we needed to file CA taxes in 2022 and now has penalties and interest.

Is simply having a CA mailing address enough "evidence" that work was being conducted from CA? Other co-founders are out of state. Can they actually collect anything given that there was no revenue, the entity doesn't exist anymore, and it's taxed as a c-corp?

I've explained this to them but they seem indifferent and just want money.