If you are using "man" to refer to humanity in general -- in other words, men, women, and children -- then you can use "he" as the corresponding pronoun. In this usage, "he" is not gender-specific.
Unfortunately, this usage is ambiguous. Unless the context is very clear that "man" refers to humanity in general, most listeners will subconsciously imagine men (not women) as the subjects of the sentence.
Constantly saying "he or she", "(s)he", "he/she", or "she/he/it" is very awkward. "He or she" is sometimes used in legal documents. "She/he/it" has a nasty (mis-)pronunciation.
In longer (non-legal) works, a viable approach is to have different people in different paragraphs or situations. Some of the people can be male, and some can be female. As A.Beth explains, sometimes "you can have examples to clarify things, and you can switch up the genders there." For example:
Alan sends an e-mail to Betty, copying Carl. Betty checks the e-mail, makes her annotations, and sends it to Carl, copying Alan.