It was a black Monday for Blackberry users yesterday, with RIM (Blackberry's parent company) admitting a major outage across North America characterizing it as a "critical severity outage".

Blackberry has about 12 million users in this part of the world. There's no word on just how many of those 12 million people were left without email. However all major Blackberry carriers iin the United States, including AT&T and Verizon were affected.

If you are a Blackberry customer, this may feel like deja vu all over again (to quote the great Yogi Berra). It was a similar story about 10 months ago.

So how does this happen? The Ziff Davis folks have actually dug up an interesting theory. Apparantly, all Blackberry email traffic goes through one of two IP addresses. Yesterday, one of those IP addresses went on the fritz. Customers routed through the other IP address were fine.

File this under "Is it me?"; but no where on either Blackberry or RIM's corporate web site can I find a presser admitting the outage. According to Reuters, RIM notified customers through email about the outage.

Through email!