A few things about the VSS solution are not clear.
It does not look as though it will do a point in time recovery to a Test or Dev DB.

Please ignore this.
Using the config file here seemed to solve the problem.
https://support.microsoft.com/en-gb/help/3186435/fix-sql-server-2016-database-mail-does-not-work-on-a-computer-that-doe

I am not sure why it worked initially and then failed when the box...


WHERE orderDateTime
    BETWEEN DATEADD(hour, 10, DATEADD(day, DATEDIFF(day, 2, CURRENT_TIMESTAMP), 0))
    AND DATEADD(hour, 17, DATEADD(day, DATEDIFF(day, 1, CURRENT_TIMESTAMP), 0))


The SQL2008 evaluation edition still seems to be available:

https://www.microsoft.com/en-us/download/details.aspx?id=1279

You had better check the licensing implications.

If you do use this, I would be inclined...

I would be inclined to disable them for at least a month first.

USE YourDB
GO
REVOKE CONNECT FROM "UserToDisable"
GO


Using Service broker, with triggers, would solve the 'connection tolerant' problem. Service broker will work with SQL Express as long as it is connecting to a non-Express edition:
https://msdn.microsoft.com/en-us/library/ms345154.aspx#sseover_topic10

You could also look at using triggers with Service Broker.
Again, conflict resolution might take some work to be robust.

I think the Sync Framework would be the normal way to approach this.
You could look at using a third party data compare tool that can be scripted. It might...

You should really provide DDL to get a good answer.
1. I strongly suspect your dates are acutally datetimes and a poor effort has been made to do comparisons.
Casting...

PLE may not be a good indicator of performance problems.
I tend to monitor waits and latency:

http://www.sqlskills.com/blogs/paul/wait-statistics-or-please-tell-me-where-it-hurts/

http://www.sqlskills.com/blogs/paul/how-to-examine-io-subsystem-latencies-from-within-sql-server/

Try:
1. Check the rights of the SQL and Agent service accouts.
2. Try doing a small backup from SSMS.
3. Try creating an agent job to do a small...

I have a number of data feeds, with shadow tables, where I maintain an archive of the Shadow table with a trigger like:

SET ANSI_NULLS, QUOTED_IDENTIFIER ON
GO
CREATE...

A filtered index might help:

CREATE UNIQUE NONCLUSTERED INDEX UQ_tblLead_Rank_LeadId
ON tblLead ([Rank], LeadId)
INCLUDE (UserId)
WHERE UserId IS NULL;
GO


I suspect the following will lock all the rows where UserId IS NULL and select the LeadId with the greatest [Rank].

 SELECT @LeadId = LeadId
 FROM tblLead WITH...

To aid searching, I would look at left justifying the area and right justifying the district.
You will probably need to take into account partial postcodes and mix ups between...