Taken from https://gist.github.com/iangmaia/3368412 and added an ignore to certain URL schemes such as mailto

gistfile1.m

- (NSArray *) extractLinksFromString:(NSString*)txt ignoreSchemes:(NSArray*)ignoreSchemes{
  NSError *error = NULL;
	NSDataDetector *detector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink error:&error];
	
	if (error) return nil;
	
	NSArray *linkMatches = [detector matchesInString:txt options:0 range:NSMakeRange(0, txt.length)];
	
	NSMutableArray *result = [NSMutableArray arrayWithCapacity:[linkMatches count]];

	for (NSTextCheckingResult *match in linkMatches) {
		if ([match resultType] == NSTextCheckingTypeLink) {
            if ([ignoreSchemes containsObject:match.URL.scheme]) {
                continue;
            }
            
			[result addObject:[[match URL] absoluteString]];
            
		}
	}
	
	return result;
}