Post Office – Dungannon, Pomeroy – Opening Hours & Branch Details Post Office is found at 5 – 6 The Diamond, 8.72 miles north-west from the centre of Dungannon. This branch looks forward to serving the people of Gortnagarn, Pomeroy, Crocknagargan, Derryhash, Cavanakeeran, Ashfad, Gortscabeen and Lime Hill. If you would like to drop by today (Friday), it is open 9:00 am – 6:00 pm. Here you can find some essential information about Post Office Dungannon, Pomeroy, including the operating times, directions and direct phone.