B2.1 Writing a formal letter or email

https://www.ielts-exam.net/general_writing_samples_task_1/1026/ Useful language

https://learnenglishteens.britishcouncil.org/skills/writing/upper-intermediate-b2-writing/more-formal-email Formal Email Example

https://learnenglish.britishcouncil.org/business-english/english-for-emails/unit-4-starting-and-finishing-emails Writing a Formal and Informal Email