If the following .dll's are removed from the bin folder after build the site loads correctly. I have listed version numbers in-case there is a conflict, I will try and narrow down one by one.
EPiServer.Common.Cache (7.0.714.0)e
EPiServer.Common.ComponentArt.Web.UI (2008.2.1204.35)
EPiServer.Common.Configuration (7.0.714.0)
EPiServer.Common.Criteria (7.0.714.0)
EPiServer.Common.Data (7.0.714.0)
EPiServer.Common.EventCounter (7.0.714.0)
EPiServer.Common.Framework (7.0.714.0)
EPiServer.Common.Framework.Exceptions (7.0.714.0)
EPiServer.Common.Framework.Impl (7.0.714.0)
EPiServer.Common.Security (7.0.714.0)
EPiServer.Common.Web.Authorization (7.0.714.0)
EPiServer.Common.Web.Authorization.Multiplexing (7.0.714.0)
EPiServer.Common.Web (7.0.714.0)
EPiServer.Mail.Configuration (7.0.442.1)
EPiServer.Mail.Core (7.0.442.1)
EPiServer.Mail.Core.EPiServer.Web (7.0.442.1)
EPiServer.Mail.Core.Web (7.0.442.1)
EPiServer.Mail.Sources.Internal (7.0.442.1)
After investigating a number of configuration keys were removed after a build due to MS build script replacing files from [Configuration] folder, I spent time comparing every item and version numbering and now have the site loading.
The version numbers are now Mail 7.0579.1 and Common is using 7.0844.1.
It seems that if you use the wizard tools it does not take into account any extra customization so this will always be a manual process.
I could not find tech notes for config file updates for manually installing EPiServer 7 Mail into an existing build but some notes on enterprise set up.
Site set up and working ok with CMS 7.0.586.1, then installed EPiServer 7 CMO module and all ok.
Then added EPiServer Mail 7.0.442.1 via deployment centre using Install Mail on existing site and now receive the following error,
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Object reference not set to an instance of an object.
at EPiServer.Common.Configuration.ConfigurationSectionBase`1.GetInstance(String sectionName)
at EPiServer.Common.ImplementationModule.LoadCoreConfiguration()
at EPiServer.Common.Settings.LoadSettings()
at EPiServer.Common.InitializationModule.Initialize(InitializationEngine context)
at EPiServer.Framework.Initialization.ModuleNode.Execute(Action a, String key)
at EPiServer.Framework.Initialization.InitializationEngine.InitializeModules()
at EPiServer.Framework.Initialization.InitializationEngine.Initialize(HostType hostType)
at EPiServer.Framework.Initialization.InitializationModule.Initialize(HostType hostType)
at EPiServer.Framework.Initialization.InitializationModule.FrameworkInitialization(HostType hostType)
at EPiServer.Global..ctor()
at Site.Global..ctor()
at ASP.global_asax..ctor() in c:\Windows\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files\root\ffbd01f6\adba04d\App_global.asax.0.cs:line 0
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I am using Configuration folder as per Alloy tech sample, I have copied keys etc., included EPiServerMail in solution EPiServerMail.config setup with same siteid as other config files, added references to .dlls.
Am I missing something based on error above, I have also built another fresh site and get the same error.