I previously overstayed my UK visa for two years. But I left voluntarily, no stamp on it, no ban and no deportation. It was 4 years ago. Last year I applied for a UK visitor visa. It was rejected and I did not appeal. Now I need to visit the Netherlands for a business visit. Will my Schengen visa application get rejected? Please advise.
There is no automatic ban.
However, you will be asked questions about prior visas, both Schengen and non-Schengen. You must answer truthfully that you overstayed in the UK and were subsequently refused a UK visa. Yes, this will decrease your chance of getting a Schengen visa. But lying and being discovered will nullify your chance of a Schengen visa.
The best course of action might be not to ask for a visa right now. If in 10 years time you have to explain one refused visa, it might be seen as an one-off incident, but if you have to explain two refused visas for both the UK and Schengen, it starts to look like a pattern.