the Fatwa Department Research Committee - chaired by Sheikh `Abd al-Wahhâb al-Turayrî
This hadîth was related by al-Daraqutnî through a man from Hâtib’s family through Hâtib that the Prophet (peace be upon him) said: "Whoever visits the Prophet after his death, it is as if he has visited him during his life."
There is an unknown man in its line of transmission, so its authenticity cannot be established.
Abû Ya`lâ mentioned this hadîth in his book al-Musnad. It was also mentioned by Ibn `Adî in his book al-Kâmil. They both narrate it with a chain of transmission containing the name of Hafs b. Abî Dâwûd who is weak in hadîth. Therefore, this narration is also weak.
Source: Islam Today