I sent an email on February 23rd and had 21 bounces, but when I sent a more recent email to the same list on March 28th, I had over 200 bounces. I can't figure out what would have caused such a huge jump. I am new to designing email campaigns, but try to stay within the recommended guidelines to avoid spam and bounces. Is there something obvious that I just don't see?
Your account hasn't been setup for email self-authentication, despite having your own domain. If there's been any changes to the filtering or security algorithms of your recipients, this lack of self-auth may be having an effect on the bounce triggers.