SymptomsWhen I upgrade Parallels Plesk Panel v. 9.x with hMailServer v. 4.x to the Parallels Plesk Panel 10.x version, Parallels Installer asks me to install the MailEnable mail server. However, I prefer to use hMailServer.
CauseParallels Plesk Panel versions released after v. 10.0 do not support hMailServer. As Parallels Plesk Panel requires a mail server, Parallels Installer prompts you to install MailEnable instead.
ResolutionInstall MailEnable during the upgrade. After the upgrade, you will have two mail servers on the machine. However, Parallels Plesk Panel v. 10.x will continue to use hMailServer; mail accounts and mailbox content will not be lost.
Use our pre-upgrade checker before upgrading to test your environment for incompatibility issues. Learn more about this here: Tool for checking business logic issues before upgrade or migration to Parallels Plesk 10.x version.