How can I trust the delivery emails/SMS are from your couriers and not from fraudsters?

The couriers that we work with have their own security/fraud awareness policies to help keep you safe from phishing/smishing attempts from fraudsters. Please take some time to read these policies to know what to expect from each courier. 

Evri: https://www.evri.com/cyber-security

DHL: https://www.dhl.com/gb-en/home/footer/fraud-awareness.html#local_alerts