Regular Expression - Maximum number of matches

Hello Folks,

I've recently added a regex to our system to flag messages with numbers those contain 10 digits.

\b^[0-9]{10}$\b appears to work well for this - but up to 40 matches. When there's more than 40 items inside a message, the pattern doesn't work. How - do you think - should I go ahead with making this work for messages with more than 40 matching items? What am I missing?

Thanks.