When a sender's email get changed, in order to preserve the completed, archived and ongoing transactions, one of the underlying solution is to invite a new sender under the main account, then assign one-to-one delegation to the new sender. This tool could help you streamlined this process in batch by inputting a CSV file.
In order to run this tool, you will need the following:
1. API key or Username + Password of your account
2. a CSV file contains sender's information. (A sample file has been included in the attachment showing you the expected header format)
Firstname, Lastname, Email are specified per sender. Company name and whether to Activate your senders immediately are set in batch.
If you encountered any questions towards this tool, feel free to make a post at the Developer Community Forums!