Reset up replication.

You turned the feature off and on so you removed the setup and all the metadata.

Speak with your email team to work this one out.

In Exchange / M365 you need to ensure the IP address of the sql servers are listed in the connect and...

You would be looking at Azure SQL Edge which is an IOT version of MSSQL Server which runs on the Pi no problem.

The only other way which I haven't tried,...

Again use the built-in replication tools.

You will be very hard pressed to do something you want to do better than replication itself that is acceptable to performance.

The only other alternatives...

No, the max server memory setting is a dynamic setting so you can change this without restarting the service.

If you look in sys.configurations DMV there is an is_dynamic column, if...

The transaction log and the memory setting have no correlation to each other.

You should treat each of them as different things to look at.

OK so max server memory at 2PB,...

The memory is high, not CPU.

CPU is only at 1.2%

What you are seeing is completely normal for SQL Server, it is very memory intensive.

Just verify you have set the SQL...

What are you most bothered about protecting.

data in transit?  Look at always encrypted

data at rest?  Look at TDE

or if you need both, look at both.

Are you sure you are using the listener for the AG as the connection point of the subscriber and not the individual replica name?

Transactional replication using modified article properties to not replicate delete statements would be the way I would do it.

What are your full requirements for this though?

Azure IaaS or Azure PaaS?

PaaS is already encrypted with TDE, you cannot turn that feature off, it is mandatory.

IaaS, look at TDE for manual enabling.

Then you have additional things to...

Distributed AGs were an Enterprise only feature (prior to SQL 2019 CU17).

So if you are running any version prior to that you can have multiple DBs in the AG and...

Yes is possible.

https://learn.microsoft.com/en-us/sql/database-engine/availability-groups/windows/replication-subscribers-and-always-on-availability-groups-sql-server?view=sql-server-ver16

https://learn.microsoft.com/en-us/sql/database-engine/availability-groups/windows/configure-replication-for-always-on-availability-groups-sql-server?view=sql-server-ver16

There is a lot of work for your application development team to do here.

Every call the the database needs to be checked for what it does.

If that call is a...