@MsKazza I have found the API documentation here https://apidoc.smtp2go.com/documentation/#/README and it looks to be straightforward to implement a new plugin based on one of my other ones.
I will need to take a closer look then I can let you know how much it might cost. That probably won't be until Monday as I am now away for a few days.
The plugins require phplist 3.3.1. If you are not using the latest release are you able to upgrade?
i'm fairly sure am using the latest i only downloaded again last week to reinstall. Monday great, np, look forward to hearing from you thanks