Ensuring zip code 11111 (or other invalid ZIP Codes) are not being treated as valid using MailStream Plus

Product Affected:  MailStream Plus™
MailStream Plus (MSP) is treating zip code 11111 (or other invalid ZIP Codes) as being valid.

On the ZIP IN parameter, position 28 controls if you want MSP to validate just the first 3 bytes of the input ZIP Code, or all 5 bytes of the input ZIP Code.

If the ZIP IN parameter position 28 has a blank value, then only the first three digits are validated :
  • Y  Check all five digits.
  • N  No, check only the first three digits.
  • blank  Default is N.

11111 is not a valid 5 digit ZIP Code, but there are valid ZIP Codes that start with 111:  11101, 11102, etc.
In this job ZIP IN position 28 was blank, so MSP only checked the first 3 digits

Once position 28  was changed to Y, then MSP considered 11111 as an Invalid zip, because it looked at all 5 digits.
UPDATED:  May 23, 2019