Microsoft Corporation's Outlook is a popular personal information manager web application. It includes webmail, contacts, a calendar, and other task services, among other things. Most people use multiple accounts to manage their many professional tasks, making the email process a little more complicated. So, to make things easier here is how to set Outlook as default mail client on Mac, Windows 10, Chrome, and Adobe. You must click on an email address such as [email protected], which will immediately launch Outlook, which you must configure first. Additionally, you might wish to set Outlook as the default software for opening email files with the.eml extension.