The Scenario
You manage a CRM at a mid-size e-commerce company. Your team is about to import a batch of 50 customers into a Thanks.io mailing list for a re-engagement campaign. The CRM export gave you email addresses in column A. Before the import, your operations manager wants to know which of these people already exist as Thanks.io recipients — either because they were in a previous campaign or were added manually — to avoid duplicating records.
You found out about this check requirement at the end of a Monday standup. The import is supposed to happen today.
The bad version:
- You log into Thanks.io and open the recipient search.
- You copy the first email from the sheet and paste it into the search field.
- You note the result in column B, go back to the sheet, copy the second email, and repeat.
Fifty lookups. Fifty copy-paste cycles. And if the answer is "yes, they exist" you also need the recipient ID for the dedup process, which means a second copy for 20 or 30 of those rows.
The Easy Way: One Prompt in SheetXAI
SheetXAI is an AI agent that lives inside your Google Sheet. It reads every email in column A and queries Thanks.io's recipient search for each one, writing the results back without you leaving the sheet.
Open the SheetXAI sidebar and paste this prompt:
For each email in column A of the Check Duplicates sheet, search Thanks.io recipients by email across the mailing list IDs in the List IDs tab and write Exists or New into column B.
SheetXAI queries Thanks.io for every email and marks each row so you can filter immediately.
What You Get
- Column B shows "Exists" or "New" for every row.
- Rows marked "Exists" let you decide whether to skip the import for those contacts or update their records instead.
- Any email that errors during lookup gets a clear status note, not a blank.
- All 50 lookups run in one prompt.
What If the Data Is Not Quite Ready
I also need the existing recipient ID when there's a match
Your dedup process needs the Thanks.io recipient ID to merge records.
Search Thanks.io for each email in column A of the Check Duplicates sheet using the mailing list IDs from cells E1 through E5 and write the matching recipient ID into column B, or Not Found if no match.
The emails have inconsistent casing
Some entries are all lowercase, some have capital letters from a form import.
Convert all emails in column A to lowercase, then search Thanks.io recipients for each one using the mailing list IDs in the List IDs tab and write Exists or New into column B, plus the recipient ID into column C if found.
I need to check across a single specific list only
This campaign is targeted at one mailing list. The list ID is in cell B1.
For each email in column A of the Check Duplicates sheet, search Thanks.io recipients in the mailing list ID from cell B1 only and write Exists or New into column B. Write the recipient ID into column C if found.
Clean the email list, remove obvious junk, and run the full dedup check
A few entries in column A have extra spaces, one has a comma instead of a dot in the domain, and three are clearly placeholder test addresses ending in example.com.
Remove rows in the Check Duplicates sheet where column A ends in example.com, strip leading and trailing spaces from all remaining emails in column A, then search Thanks.io recipients for each email using the mailing list IDs in cells E1 through E5. Write Exists or New into column B and the recipient ID into column C if found.
One prompt handles the data cleanup and the full check in a single pass.
Try It
Get the 7-day free trial of SheetXAI and open your email list sheet — ask it to check every address against Thanks.io and flag which ones already exist as recipients. Once you know which are new, see the mailing list build spoke to load the new batch into Thanks.io in one shot.