I sympathise - I got the same series...
Here's what ProZ.com staff have posted on the home page:
Repeated email notifications mistakenly sent out
A technical error allowed a job poster to post the same job almost 150 times, causing many duplicate email notifications to be sent to those who had subscribed to notifications for that type of job.
We have stopped the duplicate messages from leaving ProZ.com's mail servers, but some members may still receive many copies of this email notification.
We sincerely apologize for this problem, and are taking steps to ensure it cannot happen again.
AFAIK they managed to hold quite a few messages, but by the time the problem was noticed, quite a number had already gone out.