Electronic mail is a method of exchanging digital messages between computer users; Email first
use in the 1960s and by the mid-1970s had taken the form now recognized as email. Email operates across computer networks, which in the 2010s is primarily in Internet. Some early email systems required the author and the recipient to both on online at the same time, in common with instant messaging. Today’s email systems are based on a store-and-forward model. Email servers accept, forward, deliver, and store messages. Neither the users nor their computers are required to be online simultaneously; they need to connect only briefly, typically to a mail server, for as long as it takes to send or receive messages.
Originally an ASCII text-only communications medium, Internet email was extended by “Multipurpose Internet Mail Extensions” (MIME) to carry text in other character sets and multimedia content attachments. International email, with internationalized email addresses using UTF-8, has been standardized, but as of 2016 not widely adopted, 
The history of modern Internet email services reaches back to the early ARPANET, with standards for encoding email messages published as early as 1973 (RFC 561). An email message sent in the early 1970s looks very similar to a basic email sent today. Email played an important part in creating the Internet, and the conversion from ARPANET to the Internet in the early 1980s produced the core of the current services.
Another service we have is webmail services for our clients for free?
Webmail (or web-based email) is any email client implemented as a web application running on a web server. Examples of webmail software are Round-cube and Squirrel-Mail. Examples of webmail providers are AOL Mail, Gmail, Outlook.com and Yahoo! Mail.
Many webmail providers also offer email access by a desktop email client using standard email protocols, while many internet service providers provide a webmail client as part of the email service included in their internet service package. Proton-Mail, founded at the CERN research facility in 2013, is a Web-based email service which automatically provides secure encryption.
As with any web application, webmail’s main advantage over the use of a desktop email client is the ability to send and receive email anywhere from a web browser. Its main disadvantage is the need to be connected to the internet while using it.