Spamhuas is blacklisted my server public IP at that time i don't know about it. In current days our one customer facing issue about Sony playstation game server is not working via Our internet. Then he registered a compliant about it after some troubleshooting we find it was happend to Blacklisted public IP. So we change the public Ip and problem has been solved.
But question here, is it will happen again? As per my R&D, it will be. So may be that problem is arises due one of our clients sending Spam Mail to outside world via our internet service, & IP blacklisted
We need to prevent this in future, so i dig more and find we need to create a own SMTP server so that each mail will go though us our server through smtp domain with authentication/passwords.
All spam mails and virus will filtered by Smtp server.
But main question is, how can i achieve that still i don't know anything about it. We have 1000 customers.
All i need is your advise and guidelines. Thanks in advance