Huge Spam problem since the midweek email outage

Ever since the email outage last week, we've been getting large amounts of spam to our company email accounts. I know this is not due to any actions on our part. One of my coworkers is away from email out of the country and another is only an account I monitor. All are receiving large amounts of spam.

What is the cause and how will homestead fix the problem? I don't want to hear change our email addresses.

Who else is experiences this problem?