If you were a holder of TPM shares as at the e-rights date on 1/4/17, you should've received the notice of the rights offer. Even if, for any reason, you were not eligible to participate in the offer, you received notice to let you know of that. I suspect you may have an old address/email address registered for those holdings to explain that or something out of the ordinary like your mail being stolen.
The notice would've been delivered to you by the selected communication method you have listed with Computershare - either by email or mail. As
@stoodio said, log in to Computershare check your communication preference and address/email details - you can access these details by entering your HIN/SRN number and the postcode you have listed as your mailing address.
After you have logged into Computershare, check your communication preference and your mailing/email address to ensure it is up to date. If you have changed your mailing/email address since you purchased your shares, the notice may have been sent to an old address and you will need to update your address either through the Computershare (if you hold the shares as a issuer sponsored holding) or your broker (CHESS sponsored). To determine whether your shares are issuer sponsored or CHESS sponsored, refer to your latest holding statement or dividend statement and look whether the Shareholding Reference Number/Holding Identification Number begins with the letter 'I' (issuer sponsored) or 'X'(CHESS sponsored).
In either case, the offer has now closed so you can not take exercise the rights, but it's still worthwhile to ensure any future correspondence are delivered to you.
NB: A change of your address with your broker will change the address for all the CHESS sponsored holdings that are registered under that one HIN.
