Thank you for your email received 7 May 2015.
With regards to your query the RML tracking number can't be searched as it is not valid once the parcel leaves the UK. You would need to ask if a parcel has arrived for you by name. The post office will be able to check for this. I apologise for any inconvenience caused.
If there is anything further I can help with, please do not hesitate to contact me by replying to this email address.