I have some code on my website that sends out an email to a registered user when they have a newly generated lead. It has been working great for years. Recently I looked in the database and discovered that some of the emails are being duplicated several times. Sometimes 6-8 rows are being generated when there should only be one. This means that when my code processes the rows, and sends out the emails, that my registered users are getting spammed by me. What makes this hard to pinpoint is the fact that not every message gets duplicated.

Could this have anything to do with the fact that my ISP, where the website and database is hosted, has had confirmed problems with other mySQL users that share my same CPU?