The stinging criticism follows last month's ferocious media onslaught, sparked by the suspension of a postman for suggesting people might want to opt out of receiving doordrops.
One result of what the Daily Mail dubbed the "great junk mail revolt" was a 150,000 rise in the number of people signing up to the Mailing Preference Service. Arguments over unwelcome direct mail raged across newspapers, radio and TV for two weeks at the beginning of September.
The DMA has been slated for being caught "on the back foot" instead of educating the public about the benefits of direct mail on an ongoing basis.
"The only time we get a profile is when we are yanked up to defend the indefensible, instead of promoting direct mail," said David Laybourne, technical director at DPS Direct Mail. "And then all we do is say people can get their name taken off the (mailing) list." The DMA is now fast-tracking draft proposals for a Door-to-door Preference Service.
Graham Pugh, creative director at WDMP Communications, agreed. "This summer's crisis could happen again and get worse," he said. "We need to come out of the closet, say what we do and explain that it's not a bad thing - before it's too late. We wouldn't have been in this position if we'd been more confident in explaining what we do in the first place."
Royal Mail was criticised for allowing the "junk mail" argument to escalate.
The postal service "shot the industry in the foot" by drawing attention to the postman's actions, said Pugh. "Royal Mail has taken bread out of its own mouth."
But the DMA chairman, Charles Ping, claimed the adverse publicity had emerged as a positive PR event. An injection of £250,000 into research and PR since the BBC's Brassed off Britain programme attacked DM two years ago enabled the DMA to present a robust defence when given the platform this summer, he said.
Antony Miller, head of media development at Royal Mail, said the furore offered a chance for direct mail practitioners to take the high ground.
"This an opportunity for us to sell media with intelligence," he said.
How to avoid sending consumers 'junk mail', page 14.