We thank Ms Susan Chua Siong Ngoh for her valuable feedback ("Postal security needs to be taken seriously"; Forum Online, Dec 22, 2015).

Our customer care team has been in contact with Ms Chua to update her about our investigation.

On Dec 2 last year, our delivery staff member did not take the trolley along with her as the lift in that block does not serve all floors.

We have strict standard operating procedures for mail security, such as having our delivery personnel lock and chain the postal trolley.

We have also invested in and recently rolled out custom-made trolleys to enhance mail security and service quality.

Furthermore, the master door mentioned by Ms Chua is not the one used by Singapore Post during the course of mail delivery.

We will continue to monitor our operations in that area closely.

Lim Li Koon (Ms)

Vice-President

Group Communications

Singapore Post