This should work, but a few things I'd do to improve this:

--  Delete in batches with progress put into table

-- Table for holding progress
CREATE TABLE progress
(
...

A firewall is about access from endpoints, which may or may not help here. Inside->traffic often isn't limited, which is a hassle.

There are protections built in, but many don't use...

OPENROWSET works with limitations

https://docs.microsoft.com/en-us/azure/sql-database/sql-database-features

Usually you need a couple of scripts. One to do the blocking, one to simulated the blocked.

The easy way for the first script is have  aproc that has a WAITFOR...

You could build the SQL statement in PoSh by manipulating the strings that make it up. Or you could use parameters and a proc, changing the parameters that you send...

I mostly agree with what Brian wrote. I am wary of denormalizing, and I do it when multiple places need the data and/or performance is an issue. Trading space for...

Habits are hard to break. Good or bad, and it requires a lot of effort and desire to actually do that.

Often I try to focus on one thing I want...

good thoughts, David. Certainly focused, targeted, appropriate learning is likely an organizational concern. Managers certainly should be involved in developing people, and curating that content is something I hadn't considered,...

Glad that worked. Good luck

An index is a good idea if you're not going off id. If you are, I'd just run this in T-SQL.

https://www.sqlservercentral.com/articles/deleting-large-number-of-records

ah, sorry, I didn't read closely enough.

Are you using PoSh to control this somehow from outside SQL Server?

I'm guessing you want mail_id and then pick a range of ids to...

This might help: https://docs.microsoft.com/en-us/sql/relational-databases/system-stored-procedures/sysmail-delete-mailitems-sp-transact-sql?view=sql-server-ver15

sysmail_delete_mailitems_sp - Database Mail messages and their attachments are stored in the msdb database. Messages should be periodically deleted to prevent msdb from growing larger than...

SQL Server has the object code. The procedure code is stored in sys.sql_modules (https://docs.microsoft.com/en-us/sql/relational-databases/system-catalog-views/sys-sql-modules-transact-sql?view=sql-server-ver15), but there is no facility to retrieve this and recompile it. The nature of that...

Standard edition only supports basic AGs: https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/basic-availability-groups-always-on-availability-groups?view=sql-server-ver15

The DNS Alias is for the IP, which connects you to the endpoint.