Yahoo! IM blocks third-party access

Yahoo is planning an upgrade to its instant messaging software that will block access via third-party IM applications such as Trillian.

Yahoo representatives said on Wednesday that the company warned users of older versions of its IM client software to upgrade to newer applications or risk getting shut out of its network. Yahoo is giving users until 24 September to install current editions of its software, according to company spokeswoman Mary Osako.

According to Osako, the company is making the move in order to protect IM users from unwanted spamming from advertisers. Osako said it was necessary for Yahoo to continually develop new versions of IM in order to "prevent spammers from potentially hacking into older platforms."

She said only a small percentage of Yahoo's IM user audience need to upgrade: those still operating Yahoo Messenger for Windows 5.0 or older, Yahoo Messenger for Mac 2.0 or older and Yahoo Messenger for Unix 1.02 or older. Most users already have more recent versions of Yahoo Messenger.

However, she did say that the upgrade would likely disable access for all Yahoo Messenger users who access the service via third-party IM client software such as Trillian. Trillian is software that integrates multiple IM clients into a common interface.

"Third-party clients will likely be affected, but we're trying to communicate with other providers around the common goal of opening up the IM community," she said.

Yahoo's announcement comes on the heels of similar news from rival IM software maker Microsoft that it plans to bar third-party client software from gaining access to its MSN Messenger IM applications. On 15 October Trillian users will also lose access to the Microsoft IM client.

Trillian did not return calls requesting comment on the Yahoo announcement.

Matt Hines writes for CNET News.com