Revert "Improved mailer plugin & email by category"

This reverts commit f0c7773023bc6375491b99ee113c44c719deb94d.
Revert "Improved mailer plugin & email by category"

This reverts commit dfca4bd320b524014b7de3dd880398e247eecb7b.
Revert "Revert "Improved mailer plugin & email by category""

This reverts commit 411f906fb55659c3ed070d99a272f0d1dc7713df.