True, E-mail is usually considered as a formal mode of communication.
Explanation:
A formal mode of communication is when the information is transferred from a pre defined channel, from a top level management to the lower level of the employees.
It is considered formal because of the specific word limit that a email can carry and it is in written form. Any kind of information when conveyed in written form is considered formal because it holds authenticity. Therefore, mail is the best mode.
