Some people aren't native speakers. Do they really need to know how to spell perfectly to work for you? Perfectly, no. But in formal communications, they need

Some people aren't native speakers. Do they really need to know how to spell perfectly to work for you? Perfectly, no. But in formal communications, they need to show that they're at least making an effort to get things reasonably correct. And if it matters enough, you can always find a native-speaking friend to review your resume or cover letter for you. (Source: been there, done that, applying for jobs in other countries).