Я получил ответ
<code> NSString *encodedSubject = [NSString stringWithFormat:@"SUBJECT=%@", [subject stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
NSString *encodedBody = [NSString stringWithFormat:@"BODY=%@", [body stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
NSString *encodedTo = [to stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSString *encodedURLString = [NSString stringWithFormat:@"mailto:%@?%@&%@", encodedTo, encodedSubject, encodedBody];
NSURL *mailtoURL = [NSURL URLWithString:encodedURLString];
[[NSWorkspace sharedWorkspace] openURL:mailtoURL];