I don't think they can..... they give a day limit and mail it off via regular mail I believe. I don't know how they would track it, and not to sound rude but they aren't going to track everything for everyone.
They should have e-mail notification options and/or more updates on eCas for people though so we know the PPR is coming/expected.
I'm a little worried about the passport/receiving ect because my wife's PPR said "we are now ready to issue your immigration visas" but the eCas doesn't say anything about receiving meds ect and it's always stressful to mail a passport out. We sent it EMS with tracking number and it was seen as received in Singapore on June 7th but I think my wife was kinda confused about the whole mailing return options, she checked courier and put the envelope in ect and paid EMS for a prepaid envelope but I'm still sort of unsure if she did it right as well, I don't know if they use their own courier or will use this envelope ect so I feel your pain about the frustration of the mailing process. Just slightly concerned about your return mailing of the passport!
