I need help on writing a formal letter to introduce my company to our tenants about new management

Just be brief. Explain the intent of the letter and why the new management is excited about the venture and how it will benefit the tenants. End with an offer to help tenants with their concerns. Blah Blah.

How to introduce my company via email?

Unsolicited email might be considered spam by the recipient. We all get lots of spam and most people quickly delete them. It is best to contact via regular mail if you can.