SourceOne Email Management - Connection issues when using TLS 1.2

To support communication using TLS 1.2, install a version of the SNAC software that is compatible with TLS 1.2 before you install or upgrade the SourceOne software. If the SNAC software is installed before the SourceOne upgrade, the SourceOne upgrade process automatically updates the existing database connections to use the latest version of SNAC. If a compatible version of the SNAC software was not installed before the SourceOne installation or upgrade, use the following procedure to add new DSN connections that support the updated SNAC software.

You have a requirement to use TLS 1.2 and have connection issues when enabling.
The basic requirements for TLS 1.2 to work with SourceOne 7.26 are as follows::
1. SQL Server Native Client (SNAC) should be on version 10.5 or 11
2. Microsoft .NET Framework should be on version 4.6 or higher

SourceOne give errors "Cannot connect with database" when TLS 1.2, Triple DES 168 Cipher and the SHA Hash are enabled

Error 1:: Logon,Unknown,SSPI handshake failed with error code 0x8009030c<c/> state 14 while establishing a connection with integrated security; the connection has been closed. Reason: AcceptSecurityContext failed. The Windows error code indicates the cause of failure. The logon attempt failed   [CLIENT: 172.27.170.50]
Error 2::  Logon,Unknown,Error: 17806<c/> Severity: 20<c/> State: 14.
Error 3:: Logon,Unknown,Login failed. The login is from an untrusted domain and cannot be used with Windows authentication. [CLIENT: 172.27.170.50]

ODBC connection fails

Install the required levels of software for using TLS 1.2  details can be found in the  Installation guide for SourceOne 7.26. Page 69
https://support.emc.com/docu88257_SourceOne-7.2-SP6-Email-Management-Installation-Guide.pdf?language=en_US
When updating a system where SourceOne is already installed:
Use this driver kit:
https://www.microsoft.com/en-us/download/details.aspx?id=50402  [microsoft.com]  
If you are unable to use this driver due to site policy, let me know and I'll recommend a different one.

Install the x64 kit, it will also install the needed 32-bit drivers.

After you have it installed on all SourceOne machines:
Stop all SourceOne Activities from the SourceOne console
Stop all SourceOne services
Open the \SysWow64\odbcad32.exe
You'll have to create new connections to replace the existing ones on each SourceOne server. (if you have more than one)
The new connections have to the use the default names ES1Activity, ES1ARCHIVE and ES1SEARCH.
Note that if you have more than one SourceOne server, they won't necessarily have all three connections defined on every server.  It depends on which SourceOne software packages are installed on them as to which connections are present.
Before creating new connections:

Rename existing connections using the Configure button to change the names and then click 'Finish'. I might prefix 'OLD' onto the name as in OLD_ES1ARCHIVE
Create new ones with the default names, ES1ACTIVITY, ES1ARCHIVE and ES1SEARCH,  depending on which ones are present on the machine you are looking at.

To create the connections in odbcad32.exe

On the System DSN tab:
1) Click 'Add'
2) On the 'Create New Data Source' selection window, scroll down and select 'SQL Server Native Client 11.0'
3) Click Finish
4) On the 'Create a New Data Source to SQL Server' page, fill in these fields:
Name:  --This will be the default connection name, ES1ACTIVITY, ES1ARCHIVE or ES1SEARCH
Description: --optional, you can skip if desired
Server: Then name/instance name of the SQL server for SourceOne --I'd recommend typing this in if you can - it's quicker than waiting for the drop-down to populate usually
5) Click 'Next'
6) The default selection the 'How should SQL Server verify the authenticity of the login ID?' page is 'With Integrated Windows Authentication'.  
There's nothing to do unless you are not using Windows Authentication, in which case you'd have to select the other option and add username and password.
7) Click 'Next'
8) Select the checkbox for 'Change the default database to:'  and then select the appropriate SourceOne database for this connection,  If the names are default, the connection name matches the database name.
9) Click 'Next'
10) Click 'Finish'
11) Click 'Test Data Source'
Assuming that the test passes, you should be all set.
12) Make sure to update the existing connections on all SourceOne machines.
13) Open the SourceOne console application on the Master server.
If you can see object under 'Servers and Groups\Servers' AND under 'Native Archive\Server Configuration' , the connections are working.
14) Start the SourceOne services
15) Resume the SourceOne Activities.
16) Check the SourceOne console Operations-> Job Management to verify that jobs running - if they are expected to run now.