Exchange Server 2013: no send/receive after failed CU1- CU2 and machine restore

Question

Hi!
For several reasons, I decided to fully restore my Exchange Server 2013 machine today.
The machine is virtualized on Hyper-V.
I rebooted the server and recovered from backup and Exchange seems to be working fine. However, I cannot receive or send mail. If I try to send a message it goes to the "drafts" folder. OWA and EMC is working. I can not send mail between interna mailboxes
either. Outlook says disconnected.
When running the Exhchange Connectivity Analyzer, I get the following:
- Receive: Connection was successful but no banner was received.
- Send: Successfull. However when trying to send mail to external mailbox it does not reach that mailbox.
Mailflow was working perfectly at the time of the backup.
Help is much appreciated!
UPDATE 1: When telnet on local server i get SMTP banner. But not on other computers in same subnet.

Answer 1

OK. After fiddeling around in ADSIedit and trying to rebuild my Exchange environment I ended ut breaking it completely.
I then restored both my DC (Exchange schema CU2) and my EX (Exchange schema CU1). Scema Versions where the inconsistent as stated.
Then I uninstalled the KB2874216 successfully. After that i tried to Upgrade Exchange to CU2. The Upgrade failed at Mailbox Role: Mailbox Service With error Message:
The following error was generated when "$error.Clear();
          if (($RoleIsDatacenter -ne $true) -and ($RoleIsDatacenterDedicated -ne $true))
            if (test-ExchangeServersWriteAccess -DomainController $RoleDomainController -ErrorAction SilentlyContinue)
              $sysMbx = $null;
              $name = "SystemMailbox{e0dc1c29-89c3-4034-b678-e6c29d823ed9}";
              $dispname = "Microsoft Exchange";
              $mbxs = @( get-mailbox -arbitration -Filter {name -eq $name} -IgnoreDefaultScope -resultSize 1 );
              if ( $mbxs.length -eq 0)
                $dbs = @(get-MailboxDatabase -Server:$RoleFqdnOrName -DomainController $RoleDomainController);
                if ($dbs.Length -ne 0)
                  $arbUsers = @(get-user -Filter {name -eq $name} -IgnoreDefaultScope -ResultSize 1);
                  if ($arbUsers.Length -ne 0)
                    $sysMbx = enable-mailbox -Arbitration -identity $arbUsers[0] -DisplayName $dispname -database $dbs[0].Identity;
              else
                if ($mbxs[0].DisplayName -ne $dispname )
                   set-mailbox -Arbitration -identity $mbxs[0] -DisplayName $dispname -Force;
                $sysMbx = $mbxs[0];
              # Set the Organization Capabilities needed for this mailbox
              if ($sysMbx -ne $null)
                  Write-ExchangeSetupLog -Info ("Setting mailbox properties.");
                  set-mailbox -Arbitration -identity $sysMbx -UMDataStorage:$true -Force;
                  # No RetentionPolicy assigned to E-Discovery arbitration mailbox currently, we need to set it here.
                  # This can be remove after BUG(O15#2555914) is fixed.
                  if ($sysMbx.RetentionPolicy -eq $null )
                     $arbitrationRetentionPolicy = @(Get-RetentionPolicy -DomainController $RoleDomainController | where {$_.Name -eq 'ArbitrationMailbox'});
                     set-mailbox -Arbitration -identity $sysMbx -RetentionPolicy $arbitrationRetentionPolicy[0].Identity -Force;
              else
                Write-ExchangeSetupLog -Info ("Cannot find E-discovery arbitration mailbox with name=$name.");
            else
              write-exchangesetuplog -info "Skipping creating Discovery Arbitration Mailbox because of insufficient permission."
        " was run: "Database is mandatory on UserMailbox. Property Name: Database".
Seems the problem was corrupted arbitrary system mailboxes from previous Exchange 2010 to Exchange 2013 migration.
The solution for me was to restore the corrupted arbitrary mailboxes using this
LINK. It is for 2010 but Works on 2013.
I am now currently on Exchange CU2 on both my EX server and on my DC. Now I have to check mail flow and will report back.