A registered mail from Malaysia....
If you sent that mail via EMS, you can trace it, according to Japan Post.
If you sent that mail via another service, maybe you can trace it in Japan after it reaches within Japan Post network. Have you tried this one?
http://tracking.post.japanpost.jp/service/singleSearch....
This input form is in Japanese, while it seems that an output is displayed in English.
At Step 4 --- Give the item number to Input Box 1, omitting hyphens if any.
At Step 5 --- Click the first button.
You may fail in tracing the mail
when Japan Post has not received data on it or
when the registration service (other than EMS) which you utilized this time is not covered by this tracer.
Malaysia is listed in the following page as a country regarding which data on EMS mails are available on Japan Post side.
http://www.post.japanpost.jp/int/ems/delivery/ems_searc...
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