else if then loop for each value in table/list

Thanks so much for your assistance Anonymous!

Is there a way I can limit the table to only sender names, and handle the varying signature blocks in my query? I'm hoping the business area that use the report can update it via an Excel spreadsheet that I will use as the source. Having them manage the signature strings will be too prone to error, so I'll need to keep it simple and only as a list of names.

Additionally, removing spaces from the text is not ideal as the data is quite long (the message body) and will also be used to search for other keywords that contain spaces and other characters.