The Scenario
You inherited a suppression list from a legacy ESP. It lives in a Google Sheet — 400 rows, column A, nothing else. Your company is switching to SMTP2GO as its primary sending infrastructure in two weeks, and before the first campaign goes out, those 400 addresses need to be on the SMTP2GO suppression list.
You asked SMTP2GO support about a bulk import. They pointed you to the API. You are a marketing ops manager, not a developer.
The bad version:
- Read the SMTP2GO API documentation to find the suppression add endpoint.
- Write or borrow a script that loops through column A and fires a POST request per address.
- Debug the script when it errors on row 47 because of a trailing space in the email address.
- Run it again, then check the SMTP2GO UI to confirm all 400 actually made it through.
You are supposed to be planning the re-engagement campaign, not learning API rate limits.
The Easy Way: One Prompt in SheetXAI
SheetXAI is an AI agent that lives inside your Google Sheet. It reads column A, connects to SMTP2GO, and handles the suppression calls for you — with a writeback so you can see what happened.
Add every email address in column A of this sheet to the SMTP2GO suppression list and mark column B "suppressed" for each one processed.
What You Get
- Every address in column A is submitted to the SMTP2GO suppression list
- Column B gets "suppressed" written next to each address that was processed successfully
- Any address that fails (malformed email, API error) gets an error note in column B instead of a blank
You end up with a complete record of what was submitted and what landed.
What If the Data Is Not Quite Ready
Some addresses in column A have trailing spaces or uppercase letters that might cause API rejections
Add every email address in column A to the SMTP2GO suppression list after trimming whitespace and normalizing to lowercase. Write "suppressed" in column B for each one that succeeds.
Column A has duplicates and you want to deduplicate before suppressing
Deduplicate column A by email address, keeping the first occurrence of each. Add all unique addresses to the SMTP2GO suppression list and write "suppressed" in column B for each success, "duplicate skipped" for any that were removed in the dedup step.
You have addresses in multiple columns that all need to be suppressed
Combine email addresses from columns A, C, and E into a single deduplicated list. Add every unique address to the SMTP2GO suppression list. Write the suppression result in a new column F for each source row.
Full kill chain: clean, dedup, suppress, and report failures in one prompt
Take all addresses in column A. Trim whitespace, normalize to lowercase, and remove duplicates. Add every unique address to the SMTP2GO suppression list. Write "suppressed" in column B for successes and the error message in column B for any failure. At the bottom of column B, write a summary line: total attempted, total suppressed, total failed.
The pattern is to front-load the cleanup and let SheetXAI handle both the normalization and the API calls in one pass.
Try It
Get the 7-day free trial of SheetXAI and open the Google Sheet holding your legacy suppression list, then ask it to push every address into SMTP2GO. Once that is done, the spoke on exporting the SMTP2GO suppression list covers how to pull it back out for a hygiene audit, and the hub overview covers every SMTP2GO workflow in one place.