   The use of AI in language learning has gained increasing attention. According to Li et al. (2023), AI writing assistants can help improve learners' grammar, vocabulary, and coherence. Meanwhile, Aljanabi (2022) suggests that AI tools provide instant feedback, enabling students to recognize and correct errors independently. In the context of English correspondence, AI can function as a practical writing partner, offering suggestions on formal language use, layout, and tone, which are often areas of weakness among EFL learners.
RESEARCH METHODOLOGY
   This research employed a qualitative approach involving 24 university students enrolled in an English for Correspondence course. Students were asked to write formal letters and emails before and after using ChatGPT. Their works were assessed using a rubric covering content, organization, language use, formality, and mechanics. Additionally, participated in interviews to gather their perceptions of ChatGPT's role in supporting their writing.
1.Research Design
  This study employed a qualitative approach to analyze the influence of ChatGPT on quality of students' formal letters and emails.
2.Research Subjects
  The participants of this study werw 24 students enrolled in the English for Correspondence at State College of Islamic Studies Mandailing Natal in North Sumatra,Indonesia.The students were in their 4th and 6th semester,consisting of 5 male and 19 female students,aged between 19-23 years.
3.Data Collection Techniques
  The data in this study were collected through several instruments:
*Pre-test and Post-test Writing Task
Students were assigned to write a formal letters and a formal email before and after being introduced to ChatGPT as a writing assistamce tool.
