I want to make a mailing list from the email column of a calc spreadsheet to import into thunderbird.
I’m a little confused. If you are dealing with only one column, what will be separated by the commas?
I don’t know how to export just one column but (as a work around) you can always copy a column and paste into a new spreadsheet (which can then be saved as a CSV file).
Save your Spreadsheet as ..csv and from thunderbird: →Tools→Import....