Another thing that is really really problematic for business from time to time is weak firewall settings or weak firewalls. You want to make sure those firewalls… Basically, if you imagine that inside the castle is your business & your home and that wall outside, that’s there, is protecting you from all the bad guys coming in. That’s your firewall.
How you open the gates, and there are certain things that have to be opened up in order to conduct business. If you have your own email server Port #25 has to be opened up, or something like Port #25.
If you’re allowing remote access, something like Port #3389 may or may not be opened, or you might have another utility that uses different ports for that. But, you’re going to want to make sure that that’s configured properly and that you understand what those risks are ahead of time.