Most email are written in Russian. I don't even know what that mean. And a lot of bounced back emails. I tried filtering and not working. Any suggestions?
Are you using cpanel server ? Please use spam assassin and try to use SPF record for your domain, also make sure your domain IP address blocked in spamblock list.
try to make a r add a boot system so you ail service will get secure also use captcha system.other wise best is that called professional