Best Way To Add People To A "send Email" Command?

We have collected email addresses of customers in a spreadsheet. We plan to email these customers that a Sytist gallery will be open to preorder specific products. These customers are not currently registered on any Sytist gallery. 

Our spreadsheet has one email address per row. I know that Sytist requires email addresses have to be CSV formatted on the "send email" screen. Are there any tips to convert the data we have from an email per spreadsheet row to one line of text with "email,email,email..." to make the formatting work?

I just select to export/download my spreadsheet as a .csv - is that what you mean?

On export, your spreadsheet will read those rows as "commas separated" values.

I think you are wanting to change it to per row to emails separated by a comma?

I don't have an answer but google something like replace line breaks with a comma.

In excel

Formulas --->  TextJoin ---->  Deliminater= ,  Text = (Your Cell Range) A1:A100

Copy the the contents and paste as values. 

Copy and paste into email line in Sytist