Email is equivalent to new generations post only better. All the official works in todays life done via email even marketing is also done via it the best part is it is very fast and more reliable as you always have another copy. Also you can send it to a group email different emails and also attched almost all kind of documents in diff sizes.
And hence here comes the application designed only for email you can use any kind of email like gmail yahoomail hotmail rediffmail exchange etc in outlook
configuration is a bit complicated for 2 step verification user but you can use skype for business or teamviewer extensions directly for business meeting through it.
its also works offline you can send mail to anyone offline and when you connect online then the mail will sent .
You can add different rules create folder and assign them according to the rules
You can block different users according the rules
outlook is also comes from microsoft so a popular name with trustship
outlook is alsmost necessary for official purpose in any kind of industry even small business or now a days personal users also uses outlook because it is convinient and hassle less and once installed easy to use .