List Import Troubleshooting

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My List Import is Taking a Long Time

If you are importing a large file with a significant amount of data, the import process may take several hours to complete. Unfortunately, there is no way to speed up this process. We highly recommend planning to import a new list at least one day in advance of when you intend to email the list.

After an import begins, you will initially see a status bar. If you click away, you will otherwise be able to track the import’s progress by watching the list count increase over time. We will send you an email as soon as a list import completes.


Want to make sure your file will import? Check the list below before importing your list. 

  • CSV File (not any other format)
  • 50 MB or fewer
  • First row is headers
  • First column is email addresses
  • Every row has an email address associated with it
  • No duplicate email addresses
  • All email addresses are formatted properly 

For more information, read the associated section below. 

My File Won't Import

Your file should be a CSV file, not an Excel file. You can save any Excel file as a Comma Separated Values (.csv) file by clicking File > Save As and adjusting the file format. List imports must be in this format, as opposed to TSV (tab separated values). If you are using a version of Excel that does not use English as the default language, you may experience an error related to semicolons being used in place of commas. To remedy this, ensure that your file is in the correct CSV format.


The maximum file size allowed is 50MB. If you try to import a file that exceeds 50MB, your import will not be successful.

The first row of your file should consist of a header for each column, and all column headers must be correct in terms of capitalization/format.

You also must have one column labeled "Email" or "Email Address." If you attempt to upload your CSV and get an error that reads: “The selected file doesn’t have an Email or Email Address column," make sure the first row in your spreadsheet contains all column headers and your file contains an "Email Address" column.

My Import File Did Not Upload Successfully

There are three main reasons why your final imported list may contain fewer people than your import file:

1. Your file had a formatting issue. Check that all required columns have valid values for all rows -- for example, if there is a zero (0) in place of an email address for a row in the Email column, this will cause rows after the error to fail.

2. Your file did not contain all unique values. We will automatically de-dupe your import file for you. Before you import a file, you can check for duplicate email address entries in Microsoft Excel by clicking Data > Remove Duplicates.


3. Your file contained email addresses with an invalid format. 
We will automatically skip email address entries that are not in a valid format. A valid email address such as is made up of a local part, an @ symbol, then a case-insensitive domain part.

If any of the required parts of a valid email address are missing (such as the local part, @ symbol, or domain part), we will consider the email invalid. If there are erroneous spaces in the email address, we will also consider the email invalid. 

To search your CSV for invalid emails, you can filter based on "Does Not Contain" symbols like "@" or "." Then, you can fix or remove these addresses from your file.



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