Sending emails (メールを送る, mēru o okuru) is a fundamental part of business communication in Japan and whether they are 社内編 (shanai-hen, within your own company) or 社外編 (shagai-hen, outside your company) getting the language correct is crucial to success.
Writing a work-related email in Japanese might seem intimidating at first since you need to know when to use 尊敬語 (sonkeigo, honorific language) and 謙譲語 (kenjōgo, humble language), but by mastering some vocabulary and all-purpose grammatical structures you'll be emailing in no time.
The first challenge of a Japanese business email is how to address it. At the top of the correspondence, put the addressee's full 会社名 (kaishamei, company name), 肩書き (katagaki, position) if applicable and full name — each on a separate line. In order to prevent embarrassing misspellings, I recommend copying and pasting titles and names from the addressee's email signature as much as possible so you don't make any mistakes with their kanji. Don't forget to include the honorific title 様 (sama) after their name, which also goes for names on correspondence sent by post.