Does anyone have any more details about these Pillar Box cancellations? I am intrigued since I don't recall ever seeing similarly-worded postmarks from any other countries, and I could find very few details online regarding how/why they were used.
I found some information at the following link: http://www.postmarks.co.za/PH%20Mau...%20Louis.htm
This mentions that there were at least six types of these postmarks, five reading "Pillar Box / Port Louis" and one "Pillar Box / General Post Office" - all of these were used at the Port Louis GPO. The website cites The Postal History of Mauritius
by Proud and gives the recorded dates of use of each postmark, which range between 1881 and 1952.
However, it does not give any additional information such as why these postmarks were used in the first place. Wasn't the majority of mail posted in pillar boxes? If so why was it necessary to have a postmark reading "Pillar Box"?
Do any members have a copy of the Proud book which might give some additional details?
It would also be interesting if anyone knows something about these postmarks' value (either on loose stamps or covers/postcards).