For those unlucky enough to choose an email host that doesn't have built-in spam detection, it can often be an ordeal to route email correctly through a third-party filtering service. Some businesses actually prefer engaging with a third-party spam filterer, mostly for compliance or customization reasons. But, for the majority of SMBs, this is headache they would be best off trying to avoid.

For special purposes, such as network testing, documentation, and other applications, IANA also reserves a set of special-use domain names.[15] This list contains domain names such as example, local, localhost, and test. Other top-level domain names containing trade marks are registered for corporate use. Cases include brands such as BMW, Google, and Canon.[16]

Domain names can be used in a number of ways. Direct visitors to your website’s home page or use complementary domains to send them to specific areas of your website ( e.g. for a careers page). Or, forward a custom domain to an existing social media account, like your Twitter profile or Periscope channel. With a domain name you can even set up custom email addresses like [email protected], which can be used to conduct business or communicate with your followers. More.
A domain name consists of one or more labels, each of which is formed from the set of ASCII letters, digits, and hyphens (a-z, A-Z, 0-9, -), but not starting or ending with a hyphen. The labels are case-insensitive; for example, 'label' is equivalent to 'Label' or 'LABEL'. In the textual representation of a domain name, the labels are separated by a full stop (period).
Udemy has been a great help to the programmers when it comes to learning new skill sets and they find tutorials in any subject they want. If we specifically talk about studying web design online, the website offers multiple top-quality free and premium courses. People are free to start teaching their own courses on Udemy, so the quality and price varies.
Technical contact. The technical contact manages the name servers of a domain name. The functions of a technical contact include assuring conformance of the configurations of the domain name with the requirements of the domain registry, maintaining the domain zone records, and providing continuous functionality of the name servers (that leads to the accessibility of the domain name). 

Domain names are formed by the rules and procedures of the Domain Name System (DNS). Any name registered in the DNS is a domain name. Domain names are organized in subordinate levels (subdomains) of the DNS root domain, which is nameless. The first-level set of domain names are the top-level domains (TLDs), including the generic top-level domains (gTLDs), such as the prominent domains com, info, net, edu, and org, and the country code top-level domains (ccTLDs). Below these top-level domains in the DNS hierarchy are the second-level and third-level domain names that are typically open for reservation by end-users who wish to connect local area networks to the Internet, create other publicly accessible Internet resources or run web sites.
One of the most important compatibility factors to consider with email is the mobility question. How often do your employees need to access email via mobile devices? That's an important issue because most email hosting providers deliver some kind of web client usable as a default inbox. Almost all of these can be accessed via a mobile device, so if your employees don't need to access their emails on the road that much, then such mediocre clients are probably fine.