A disclosed example method to monitor an email system involves sending a first test email from a first email system to a second email system. The first test email is addressed to a first destination email address associated with the second email system and having first information identifying the first test email and the second email system. The example method also involves retrieving, from an email account having a second destination email address different from the first destination email address, a plurality of other test emails from other email systems being tested for operability. The other test emails include second information identifying corresponding ones of the other test emails and corresponding ones of the other email systems. The example method involves determining whether the first test email fails to arrive at the email account within a time period from the second email system.