[header] How to write a professional mailing address on an envelope [title] Use a person's name. [step] No matter where the letter is going, it's best to address it to a person, if possible. Figure out who would be the most appropriate person for the letter to find. 
If you can't find a person's name, consider using a department, such as the hr department. [substeps] Do your research to find out who you should send it to.