 <p>you can add comma from second emailid onwards. </p> <pre><code>for (int i = 0; i &lt; dataGridView1.Rows.Count; i++) { if(i&gt;0) sendto.text +=","+ dataGridView1.Rows[i].Cells[3].Value.ToString()); else sendto.text = dataGridView1.Rows[i].Cells[3].Value.ToString()); } </code></pre>