BlackBerry users in North America were hit by service problems again on Wednesday morning.
The issue appeared to get progressively worse, initially affecting about half of users in the Americas but eventually affecting all users, according to newsgroup postings.
RIM said it was not a system-wide outage. "RIM did perform regularly scheduled maintenance on BlackBerry Internet Service that took longer than originally expected and some BlackBerry Internet Service customers may have experienced slower delivery of e-mail earlier today," the company said in a statement.
The problem affected only users of BlackBerry Internet Service and not BlackBerry Enterprise Server customers, RIM said. BIS customers sign up for the service through their mobile operators. Enterprises often use a different setup, installing a BES to deliver corporate e-mail to BlackBerry devices.
While messages to and from both BIS and BES users pass through RIM's network operations centers, in this case, only the network components that handle BIS customers were affected.
One BlackBerry user posted a note on the newsgroup that he said came from his AT&T representative. The note called it a national BlackBerry outage that could affect e-mail delivery for up to half of new BlackBerry users.
At noon on the East Coast, one user reported that AT&T said the problem was fixed but that e-mail messages might still be delayed until the backup of messages was sent out.
Some users of the newsgroup said that they were able to receive messages all morning, although they were often delayed.
RIM had an outage last week that lasted for about three hours and left users unable to send or receive messages or access the Internet. That outage followed one that occurred in January, but that one was due to a problem with AT&T's network, so it affected BlackBerry users as well as iPhone and other AT&T mobile data customers.
RIM's most notorious network problem happened last year, with an outage that lasted overnight for many users in North America.