Dilip-da corresponded with Sri Aurobindo on a daily basis, often two or three times a day, and Sri Aurobindo immediately replied at great length to all his letters. Nolini-da always delivered Sri Aurobindo's replies to Dilip-da.
Many years later, from time to time, Dilip-da also received letters from the Mother. I was Nolini-da's secretary. On four occasions, Nolini-da asked me to deliver a letter from the Mother to Dilip-da. I did not walk at that time. I practically ran from downstairs, screaming, "Dilip-da! Dilip-da! Dilip-da!"
Then he would call me up and I would give him the letter. What a beautiful, blessingful smile I used to get from him! That was Dilip-da.