Restore from 8.6 doesn't restore Mail

[jgpcandrepair]

I had a psa backup from a server running Plesk 8.6 with hMailserver. When generating the backup, I made sure to select the option for general mail backup for any mail server. I went through the conversion process to get the backup 9.0 friendly, and after restoring everything, the mail accounts were created but the mail data was not restored. On the new server I have the included Mailenable standard server. What can I do to get the mail data restored?