A man who allegedly robbed a postman of his mailbag has been charged with a number of offences.

Police say about 8.40am (AEDT) on Thursday, a 49-year-old man who was delivering mail near Memorial Drive in Liverpool was accosted by three men as he rode past them on his motorcycle.

One of the men allegedly grabbed him, tearing his jacket. The attacker then took the mailbag from the side of the motorcycle, police allege.

The postal worker was able to ride to a nearby home to alert police.

A man from Ashcroft was arrested near the scene and charged with robbery, destroy or damage property, and breach of bail.

He was refused bail to appear in Parramatta Local Court on Friday.

The postman was uninjured and all the mail was recovered.