Mass email improvement: change the address used in place of "to"

[tahmidrahman-dsi]

Instead of using the first receiver as “to”, it’s more common to use the sender’s address

[rikukissa]

There is a privacy aspect to this task, which is that currently all receivers of the mass email see the first receiver's email as the "to" address. In most cases however, this would be the address of the first user created in the system (OpenCRVS super admin). Is this correct @tahmidrahman-dsi ? If yes, then I think this is low priority. Otherwise high.

[tahmidrahman-dsi]

@rikukissa everyone sees the super admin email (first user created in the system) as the "to" address