The Royal Mail has unveiled plans to leave parcels or post which needs to be signed for with a neighbour if a householder is not at home.
The postal organisation also said it wants to amend the amount of compensation to business customers, so that no payment would be made for loss or damage for those using "untracked" services.
The plans would not affect consumers or most small business customers who use stamped and franked mail and parcels, it said.
Royal Mail is the only major delivery company which does not deliver undeliverable items to a neighbouring address as part of its standard practice. Under its existing licence, Royal Mail is prevented from delivering to a neighbour if the recipient of the mail is not at home and the item is too large for the letter box.
In a recent survey, leaving an item of mail with a neighbour was the most popular location for delivery when no-one was at home to receive the mail.
Stephen Agar, Royal Mail's director of Regulated Products, said: "The way we all use the post is changing rapidly. We are seeking approval to make some changes to the services we provide which better reflect today's postal market."
But Robert Hammond of Consumer Focus, said: "The regulator must look long and hard at whether these moves are in customers' interests and whether they are warranted. While changes to keeping undelivered mail are sensible the proposals on compensation and leaving mail with a neighbour would cut consumers' rights, leaving many losing out.
"We do not support reducing compensation claim times from a year to two months, as Royal Mail admits that almost a third of customers take more than two months to claim.
"As you can't claim in the first 15 working days after posting this would effectively leave customers with only six weeks to claim. Changes in business compensation could also see costs increase for cash-strapped customers.
"Some consumers will like the idea of being able to have mail left with a neighbour. However, worryingly there is no opt-out option and for many people having their mail left with a neighbour they do not know, or might not trust, could open the door to problems."