Now instead of a 10 minute walk, they face five-mile journey to pick up mail.
The East End residents condemned the move to close the G31-G40 office on Cubie Street in Bridgeton, which will force them to travel to Cambuslang to collect parcels.
The Royal Mail confirmed that the delivery centre will close at the end of January 2013 and all services will be relocated to South Lanarkshire.
Frank Plowright, 53, from Dennistoun, said: "It is about a mile for me to walk to Cubie Street. Cambuslang? I don't even know where it is.
"I think it will hit elderly people really badly, especially at Christmas. It will add to the stress and concerns – with phones not answered and parcels not delivered."
Dennistoun residents Veda Houston and Mary Gallagher both said they did not think the sorting office should be closed.
Veda, 70, said: "They should keep it open, because some people can't travel.
"It would be a blow to the community. I would miss it because I use it quite a lot."
Mary, 69, added: "The people who order parcels would miss out, a lot of people never see a neighbour to leave a parcel with."
The Bridgeton office is not the first in the city to be marked for closure.
The Greater Pollok sorting office was relocated to Craigton last month and the Rutherglen sorting office has also been moved to Cambuslang.
Royal Mail say the the changes are down to different usage patterns at post offices.
Overall mail volume is declining by around 6 per cent per year and there are now many more packages than letters, making some sorting offices obsolete.
But the closure of local offices is a major concern for some communities.
John Mason, Bridgeton's MSP, said: "This is deeply concerning news.
"A number of big questions remain outstanding, for example, what local consultation was carried out with residents?
"Public transport from Bridgeton to Cambuslang is practically non-existent.
"This is just a real concern for my constituents and I fear this hasn't been thought through properly.
"Asking people to travel from Bridgeton to Cambuslang just to pick up a large envelope is a nonsense and I seriously hope the Royal Mail will pause and reflect on this."
MSP Paul Martin, who represents Dennistoun, added: "This is unacceptable and we will be looking for the Post Office to reverse their decision."
Royal Mail spokeswoman, Julie Pirone, said: "The planning for all aspects of this move is in the very early planning stages.
"Faced with declining mail volumes and increasingly tough trading conditions, Royal Mail constantly reviews the operational efficiency and commercial practicality of all its units.
"As part of our business-wide modernisation programme, Royal Mail is investing in new technology and equipment and upgrading operational facilities in order to ensure that we have world class facilities which provide the most efficient and effective network for delivering the post."