We are using ImapClient to read email items from a specific folder served by MS Exchange. The app uses the ImapClient.ListMessages() method to populate an ImapMessageInfoCollection from which we iterate through the ImapMessageInfo objects. For each ImapMessageInfo object, we retrieve a MailMessage object using ImapClient.FetchMessage() method, passing the UniqueId from ImapMessageInfo.
In our development environment, email messages with html bodies come through with MailMessage.HtmlBody populated and MailMessage.IsBodyHtml 'true'. The same email messages in the production environment come through with HtmlBody not populated and IsBodyHtml 'false'.
We would like to have HtmlBody populated in production. What determines whether or not HtmlBody is populated and IsBodyHtml is set to 'true' or 'false'?