Security and anti-spam improvements to Yahoo’s Webmail service are being rolled back because they interfered with users' ability to retrieve POP e-mail from external accounts.
Yahoo has tried for about a week to solve the problem, which arose after it beefed up spam filtering and added SSL (Secure Sockets Layer) capabilities to Yahoo Mail's POP (Post Office Protocol) functionality.
However, whatever caused the problem has proven harder to solve than anticipated, so Yahoo has decided to roll back the anti-spam and SSL features.
The goal is to restore the affected POP retrieval capabilities and add the new features later, once the problem has been properly identified and solved.
Yahoo Mail is a company crown jewel and a key piece of its ambitious plans to boost advertising, increase traffic, attract more developers and better compete by giving its users a "social profile" dashboard to unify and manage their Yahoo services.
The unresolved problem comes as Yahoo faces turmoil around Microsoft's acquisition offer and a looming shareholder proxy fight to oust current board members.
The rollback of the SSL and anti-spam features is under way and will take "a few days" to reach all users, wrote Ryan Knight, Yahoo Mail Community Manager, in a blog posting Monday afternoon.
"What this means is that your ability to retrieve from these accounts should be completely restored, however it also means that we will be rolling back the recently added option to use SSL. If you have added an account that requires SSL, retrieval from that account will no longer be possible," Knight wrote.
Knight first acknowledged the problem in the Yahoo Mail blog on 3 June, when he informed users that the company's engineers were already rolling out a fix.
The problem persisted, however, and on June 6 Knight wrote that, despite the fix, outstanding issues remained and that Yahoo would continue seeking a solution.
He also explained the new features whose rollout led to the problems: "Recently we made some changes to how external account retrieval works. Most notably we added SSL functionality (enhanced security technology), which many users have been clamouring for.
“We are also taking steps to improve spam blocking for messages that are being retrieved from these external accounts, by running them through more aggressive filters. Unfortunately we encountered some unexpected problems that lead to server errors or processes timing out for some users," he wrote.
On Tuesday afternoon Yahoo spokeswoman Kelley Podboy confirmed that Monday's blog posting from Knight contained the most recent information available about the issue. "We are also sending direct e-mail to all users who have recently enabled SSL external accounts to notify them of the change," Podboy said.