Could you please check the following,
Open your backup.zip and edit the DB XML file (XXXXXXXXDb.xml)
Go at the bottom and confirm the following section,
<mailSettings>
<mailServerHost>smtp001.3cx.com</mailServerHost>
<mailServerPort>25</mailServerPort>
<mailFromAddress>
[email protected]</mailFromAddress>
<mailServerUser></mailServerUser>
<mailServerPassword></mailServerPassword>
<mailServerUseTLS>False</mailServerUseTLS>
</mailSettings>
<generalSettings>
<backupPath>D:\Backups</backupPath>
<recordingPath>D:\Recordings</recordingPath>
</generalSettings>
Can you confirm that they point to the new path and you have your smtp settings specified?
If no this means that you are using an old backup which in previous builds we did not use to save this parameters inside backup nor restore.
If you have everything saved inside backup then restore this backup and provide restorecmd log if you are restoring via Web Management Console. If you are restoring via PbxConfigTool than provide pbxconfig tool.
Let me know thanks