Ensuring the security and deliverability of emails from your business accounts is important. SPF, DKIM, and DMARC represent the three pillars of email security. But what are they, and how do they shield you from potential email threats?
DNS Server
Do you find your custom DNS server entries being deleted after every reboot or after every disconnection? Do you use DHCP but still want to use your own DNS servers? Do you want to use OpenDNS and ignore the DNS servers provided by your ISP? Well here is how you can do this on Ubuntu. This solution applies to Ubuntu but might very well work for other distributions of GNU Linux as well.