AOL denied today that it blocked customer e-mail that includes links to a group opposing the company's proposal to begin charging a voluntary fee for certain e-mail.

Thursday, the DearAOL.com Coalition issued a press release charging AOL with blocking all e-mails with links to the coalition.

"Over 150 people who signed a petition to AOL tried sending messages to their AOL-using friends and received a bounceback message informing them that their e-mail 'failed permanently,'" the coalition stated.

AOL spokesman Nicholas Graham admitted the mail bounced but dismissed it as a software glitch that has been fixed.

"The mail is being delivered as usual," Graham said. "We discovered a technical glitch on Thursday and it was fixed by Thursday evening."

Graham said the glitch affected links to more than 50 sites with "absolutely no commonality."

In February, AOL raised a firestorm of controversy when it announced a "voluntary, additional layer of e-mail delivery" that will make it possible for companies to buy a sort of digital postage for assurance that their e-mail will be delivered to their customers.

AOL said the proposal, which has yet to be instituted, was an attempt to decrease the spam and identity fraud scams that plague the Internet, stressing the company will retain its free e-mail services, the AOL Whitelist and Enhanced Whitelist.

The plan drew immediate criticism from a number of groups, including the Electronic Frontier Foundation, MoveOn.org, Free Press and the Gun Owners of America. Since launching in mid-February, the DearAOL.com Coalition claims to represent more than 15 million people.

The group says since the beginning of the campaign to stop the AOL plan, more than 350,000 Internet users have signed letters to AOL opposing the proposal.