Validation Rule for the Postal Code Format?

Hi,

Could anybody provide the validation rules for the following formats?

1 <u>Postal code :</u>

Format of Postal Code or PO Box Postal Code needs to be 9999 XX (4 digits + space + 2 characters)

2 <u>Email address:</u>

Validate the Email format

3 Check the numeric Only

4 Check the character only

5 specific value check

IF(TYPE = s, "enter the street only")

is it possible to give the my own error message like "enter the street only"

Looking for the answers.

Best Regards

Devaraj PK

<b>Points will be given for the relevant answers.</b>