1-15-2020 - Guide updated with the new Terms and Conditions.

4-16-2021 - Guide updated with the new Terms and Conditions as of 3-22-2021, TEM environment information, new Mail.XML 24 release, and minor edit.

4-30-2021 - Guide updated with the new Terms and Conditions as of 4-23-2021.

3-14-2022 - Guide updated with the new Mail.XML version 25, including new fields added to the Campaign Data block.

7-1-2022 - Guide updated to reflect implementation of the new Informed Delivery fields and minor edits and updates. 

6-1-2023 - Guide updated with current supported Mail.XML versions including version 26 for PostalOne! Release 58.0.