problem with validating tanzanian postal addresses.

[God knows]

I am developing an application which needs a user to input his/her postal address during registration.

I have broken the input into two fields: postal address and postal town/city as shown below.

The problem comes with validation. I need to know the following information if any:
- The lowest and the highest address in Tanzania. The aim here is to prevent someone from entering addresses such as P.O.Box 5987697487987694768679849848, while not denying service to any one.
- Is there database of postal centres/towns/cities?

This information needs to be as accurate as possible because we will be emailing registered users some information later on through their postal addresses.

Any help is appreciated. Thanks!

 

[Chief-Mkwawa]

nafkiri vitabu vya yellowpages vina hio database, ila muda sijaviona, wateja wa TTCL ngoja watakuja kujibu kama bado vipo.