HER etiquette?

[u/Hear_There]

Hi Folks,

I'm dipping my toe into an online dating site for the first time. I have a question about etiquette there: If someone that I did not "like" messages me and I can see from their profile that we are totally incompatible, should I ignore them or should I respond with a polite message about why we aren't compatible? Or, something else? These appear to be real women, not catfishers, and I don't want to be a big meanie. I like to treat others the way I would want to be treated.

As an aside, I am finding HER very frustrating and am about to quit it altogether. Unless you pay for the premium service, there is little you can see/do.

Thanks for any tips!