Since I launched GMass about nine months ago, several users have asked me to make it possible to email duplicate email addresses in a Google Sheets spreadsheet. While in most cases, a user prefers that GMass de-dupe an email list, there are certain cases where de-duping isn't appropriate.
Now when you connect to a Google Sheets spreadsheet, there is a checkbox you can check which will allow you to keep duplicate email addresses.![]() |
| There is a new checkbox to "Keep Duplicates". |
If the
Keep Duplicates option is checked, then GMass won't de-dupe your email addresses, and you can send multiple email messages to the same email address, with different values from the different rows in the spreadsheet. For example, let's say you're an after-school activities program, and you're emailing the parents of children who are registered for a program. A parent might have multiple children registered, and therefore the parent may need to be sent several personalized emails, all at the same address, one with each child's registration information.
![]() |
| An example of a spreadsheet where you don't want to de-dupe your list before emailing. |
In the spreadsheet above, the parent "Joan Smith" has three children registered for three different classes. In this case, the program administrator wants Joan Smith to receive three different emails, one with each child's class registration information.
Note that when the Compose window is launched, the multiple instances of the address joansmith@yahoo.com are slightly altered by GMass so that GMass can associate each address to the right row in the spreadsheet. This is normal, and you should not alter the "-GMassX" tag that is added before the @ sign. When the emails are actually sent, these are removed from the email address.
![]() |
| After GMass connects to a spreadsheet and "keeps duplicates", multiple instances of the same email address are tagged. |
