email-verification

Original：🇺🇸 English

Translated

Validate email addresses before campaign sending. Takes a contact CSV, validates each email via a verification provider, removes invalid/do_not_mail/abuse/unknown addresses, and optionally cleans them from sequencer campaigns. Outputs a verified CSV ready for campaign-sending. Fits between email-generation and campaign-sending in the pipeline. Triggers on: "verify emails", "validate emails", "email verification", "clean emails", "check emails before sending", "remove bad emails", "email hygiene".

2installs

Sourceextruct-ai/gtm-skills

Added on2026-03-28

NPX Install

npx skill4agent add extruct-ai/gtm-skills email-verification

SKILL.md Content

View Translation Comparison →

Email Verification

Validate emails before sending. Sits between

email-generation

and

campaign-sending

:

email-generation → email-verification → campaign-sending

Environment

Provider selection and credentials are handled in Step 0 of the workflow.

Inputs

Input	Required	Source
Contact CSV with email column	yes	From `email-generation` output or any CSV
Sequencer campaign IDs	no	From `campaign-sending` — only if cleaning uploaded leads

Workflow

Step 0: Confirm provider and learn API

Ask the user which email verification provider they want to use.
Fetch or read the provider's API documentation and identify:
- Credit check endpoint
- Single email validation endpoint
- Required input fields and authentication method
- Rate limits and request constraints
- Response format (status, sub_status)
- Status values and which to keep vs remove
Ask for their API credentials and confirm access

Step 1: Check API access and credits

Call the provider's credit check endpoint
Count unique emails in the input CSV
If credits < unique emails, warn the user and ask whether to proceed with partial validation or stop

Step 2: Extract and deduplicate emails

Read the input CSV, auto-detect the email column (common names:
```
email
```
,
```
Email
```
,
```
email_address
```
)
Build a set of unique email addresses
Skip rows with empty/missing email

Report:

{N} unique emails to validate, {M} rows without email skipped

Step 3: Validate emails

For each unique email, call the provider's validation endpoint:

Respect the provider's rate limits (from Step 0)
Print progress every 50 emails
Store results as
```
{email: {status, sub_status}}
```
On error (timeout, JSON parse failure), mark as
```
unknown
```

Step 4: Categorize and report

Group results by the provider's status values. Use the status mapping identified in Step 0 to determine which emails to keep and which to remove.

General guidance (confirm against provider docs):

Action	Typical statuses
Keep	`valid` , `catch-all` (flag in report)
Remove	`invalid` , `do_not_mail` , `abuse` , `unknown` , `spamtrap`

Present summary table with counts per status, then list all emails to remove with their status and sub_status.

Step 5: Output cleaned CSV

Filter the original CSV: keep only rows where email status maps to "keep"
Write cleaned CSV to same directory as input, named
```
{original_name}_verified.csv
```
Save full validation results to
```
{original_name}_verification_results.json
```
for reference

Report:

{kept} emails kept, {removed} removed, {catch_all} catch-all (flagged)

Step 6: Clean from sequencer (optional)

If the user provides sequencer campaign IDs:

Ask which sequencer they use (Instantly, etc.) and read its API docs from
```
skills/campaign-sending/references/
```
For each removed email, call the sequencer's lead deletion endpoint
Respect rate limits
Report:
```
{N} leads removed from sequencer
```

If no campaigns are provided, skip this step and note that the user should remove bad emails manually or re-upload with the cleaned CSV.

Output

File	Contents
`*_verified.csv`	Cleaned CSV with only valid emails
`*_verification_results.json`	Full validation results for all emails
Console report	Summary table + list of removed emails

API References

Provider API docs are fetched or read during Step 0. No pre-configured provider docs are bundled — add them to

references/

as needed.