The Royal Mail worker was on his rounds on Bentley Road when a group of youths outside a shop threatened and gathered around him after he challenging them after spotting them attempting to remove parcels from his bag.
The moment was captured on CCTV camera and a video of the incident was widely shared on social media but has now been deleted.
It is not clear when the footage was filmed but the clip had been shared on Facebook in recent days before being removed.
The footage shows the delivery worker, dressed in red, walking along Bentley Road near to Bentley Convenience Store.
He briefly leaves his delivery trolley on the path as he goes to make a delivery and while he is away, a pair of youths can be seen attempting to remove items from the bag.
After confronting them, a verbal exchange takes place with the postman continuing on his rounds.
However, more words are exchanged and a number of the group pursue the postal worker with a physical altercation taking place as the group jostle around him.
Drinks are then hurled in his face, with the force and shock of the attack sending the worker’s cap into a nearby garden.
A Royal Mail spokesman said they were unable to comment after the video was deleted but a spokesman said: “We are shocked and saddened to hear that someone has reportedly been attacked.”