With the incremental integration of technology in writing assessment, technology-generated feedback has found its way to take further steps toward replacing human correcting and rating. Yet, further investigation is deemed necessary regarding its potential use either as a supplement to or replacement for human feedback. This embedded mixed-method research aims to investigate three groups of Iranian intermediate IELTS applicants who received automated, teacher, and blended (automated + teacher) feedback modes on different aspects of writing when practicing for the writing skill of IELTS. Furthermore, a structured written interview was conducted to explore learners’ perception (attitude, clarity, preference) of the mode of feedback they received. Findings revealed that students who received teacher-only and blended feedback performed better in writing. Also, the blended feedback group outperformed the others regarding task response, the teacher feedback group in cohesion and coherence, and the automated feedback group in lexical resource. The analysis of the interviews revealed that learners had high opinion regarding the clarity of all feedback modes and learners’ attitude about feedback modes were positive. However, they highly preferred the blended one. The findings suggest new ideas that can facilitate learning and assessing writing and recommend that teachers provide comprehensive, accurate, and continuous feedback as a means of formative assessment.