When you changed to datetime2 did you use datetime2(7)? That seems to have the same valid range at informix date data type.

You are defaulting @criteria to null so null concatenated with any string is null.

UPDATE a SET
   a.Address1 = b.Address1
 , a.Address2 = b.Address2
 , a.city = b.city
 , a.stateAbbrev = b.stateAbbrev
 , a.phoneNumber = b.phoneNumber
 , a.email = b.email
 ,...

This or this should help

Look at the reports included in SSMS. Right click the server and choose Reports_>Standard Reports

SELECT
     Min(o.HistoryDateTime2) BegDt
   , Max(o.HistoryDateTime) EndDt
   , o.IndicatorID
   , o.HoldingID
FROM #OutputTable o
GROUP BY o.IndicatorID
       , o.HoldingID;


Is the email coming from the package?

You could create an after delete trigger and insert deleted into a delete history table. You could add a column for SUser_Name() to track who made the delete if they...

What version of SQL server are you using?

Use SSIS and schedule a job to run it.

USE Jic
GO
CREATE TABLE dbo.abc (Month_Name nvarchar(10) NOT NULL PRIMARY KEY)
GO
INSERT dbo.abc ( Month_Name )
VALUES (N'APRIL')
     , (N'AUGUST')
     , (N'DECEMBER')
     ,...

https://docs.microsoft.com/en-us/sql/t-sql/statements/create-fulltext-index-transact-sql?view=sql-server-2017