If your source data contains special characters like accented letters, Chinese characters, or non-English alphabets, you'll need to save your source data differently.
Instead of using a CSV file, when saving your spreadsheet in Excel select the "UTF-16 Unicode Text" option. This will create a TXT file.
When creating the mail merge, use the "upload recipient list (csv)" option, selecting your TXT file.
Mail Merge requires a Premium or Enterprise level plan.
Mail Merge is available using our legacy add-in within Outlook Exchange