3402638 - Error While Importing "Data file does not follow CSV specification. Contact system admin."

Check for comma( ‚ ) or any other invalid character present in the fields Attachment Name and File path in manifest.csv file and then remove or replace it with an alphabet 

Upload the file again once the special characters are removed. Notice that there are various special characters like: "\", "/", ":", "*", ", "<", ">", "|", ".", """, "$","[", "]" that should be revisited.

In order to be assertive while correcting, collect the correct template and tested it further. 

After treating your original data, specially in relation to ": " records, no errors should be thrown any longer. Example of adjustment:

"From Smoke, Eddie test@test.com 
Sent Monday, June 10, 2023 10:50 PM
To SAP Support"

• Please make this corrections before proceeding with further imports in order to avoid such erroneous scenarios.
• Remember to always past data without data format in the template file.

Basically this work of removing special characters aims to exclude polluted format in your file.