You can use the Sendgrid block "Send email with CSV attachment", to send an email that has one CSV file attached.
This block has an input "Attachment CSV Content", which should be an array of objects. The keys of each object are ignored, the values are placed in the CSV line.
"ignored_key 1": "csv value 1",
"ignored_key 2": 123
"second_line_ignored_key 3": "csv value 3"
This will result in following CSV content:
"csv value 1", 123
"csv value 3"
Here's an example Blend, that loops over contacts from a CRM. We use a variable of type Object to define the values that will be placed in one CSV line:
Remember, the keys ("column1", "column2" and "column3" above) are ignored.
We add this object to a second variable of type list:
This list becomes the input of the Sendgrid block: