Here are a some legitimate websites that provide work-from-home opportunities in online customer service and other fields:

Upwork - a freelancing platform where you can find customer service and other remote jobs.

FlexJobs - a job board that curates flexible and remote job listings from various industries, including customer service.

Amazon - offers virtual customer service positions where you can work from home.

Apple - hires remote advisors for their customer service department.

LiveOps - offers work-at-home opportunities for customer service representatives.

Sykes - provides virtual customer service positions for various industries.

Concentrix - offers remote positions for customer service representatives.

Working Solutions - hires remote workers for customer service, sales, and technical support positions.

Lionbridge - offers remote positions for customer service and other roles in various industries.

Kelly Services - offers work-from-home positions in various industries, including customer service.

While these websites are legitimate, it is still necessary to conduct your own research and due diligence before applying for any job opportunity. Always look for reviews and testimonials from current or former employees, and never give out personal information or pay any upfront fees to a potential employer.