Fast, statically linked email list validator in Rust — zero runtime overhead.
Email Validator extracts, deduplicates, and validates email addresses from any text source (TXT, Markdown, XML, CSV, STDIN pipes). Three validation modes: regex only, MX lookup, or full SMTP handshake.
# Simplest usage: file in, validated list out
email_validator -i input.txt -o verified.txt
# Regex-only validation (no network)
email_validator -i mails.txt -m regex
# GoPhish CSV output format
email_validator -i mails.txt -o out.csv -f gophish
# JSON output for n8n / API / automation
email_validator -i mails.txt -j | jq
# Via pipe (STDIN)
cat mails.txt | email_validator -f listThe binary is statically linked (musl), compressed with UPX, and runs on any Linux x86_64 — Alpine, Arch, Debian, Ubuntu, CentOS, embedded systems. No glibc, no runtime dependencies.
Simply make it executable and go:
chmod +x email_validator
./email_validator -i emails.txt -o clean.txt| Flag | Description | Default |
|---|---|---|
-i |
Input file (optional, STDIN otherwise) | — |
-o |
Output file (optional, STDOUT otherwise) | — |
-m |
Validation method: regex, mx, smtp |
smtp |
-f |
Output format: list, gophish |
list |
-j |
JSON array output (conflicts with -f) |
false |
-d |
Disable wildcard domain check | false |
-v |
Verbose mode | false |
| Method | Description | Network |
|---|---|---|
regex |
Syntax check via RFC-compliant regex | ❌ |
mx |
Regex + MX record lookup of domain | ✅ |
smtp |
Regex + MX + SMTP handshake (RCPT TO) | ✅ |
| Flag | Format | Includes |
|---|---|---|
-f list (default) |
One valid email per line | Valid only |
-f gophish |
CSV: First Name,Last Name,Email,Position |
Valid only |
-j / --json |
JSON array | All emails (valid + invalid) |
Designed for n8n, automation pipelines, and API consumption. Each email is an object
with email, valid, and optionally catch_all (only present when true):
[
{ "email": "alice@example.com", "valid": true },
{ "email": "bob@catch-all.tld", "valid": true, "catch_all": true },
{ "email": "nobody@no-mx-xyz123.de", "valid": false }
]Use with jq for filtering and transformation:
# Extract only valid emails
email_validator -i mails.txt -j -m smtp | jq '[.[] | select(.valid)]'
# Pipe directly into n8n webhook
email_validator -i mails.txt -j -o result.jsonThe regex parser reliably extracts emails from:
- TXT — prose, lists, CSV exports
- Markdown — links, code blocks, tables,
mailto:links - XML — attributes, CDATA sections, text nodes
- HTML — tags, attributes, plaintext
- Any mixed content with noise, special characters, and broken entries
Duplicates (including case-insensitive variants) are automatically detected and removed.
# Clone the repository
git clone https://github.com/USERNAME/email_validator.git
cd email_validator
# Build a static binary (requires musl toolchain)
rustup target add x86_64-unknown-linux-musl
cargo build --release --target x86_64-unknown-linux-musl
# Optional: compress with UPX (~8 MB → ~3 MB)
upx --best --lzma target/x86_64-unknown-linux-musl/release/email_validatorRun tests (32 total, all green ✅):
cargo test
# Regenerate diagrams (requires plantuml)
cd doc && plantuml *.pumlModule-level docs for all internal types and functions.
👉 Developer Docs — live on GitHub Pages.
cargo doc --no-deps --openA tarball of the docs is also attached to every release
as email_validator_docs.tar.gz.
This opens a local browser with docs for ingestion, precheck,
validation, output, and all public types.
This project is licensed under the MIT License.
You may copy, modify, distribute, and use it in your own projects (including commercial software) with proper attribution.
- Rust (Edition 2024)
- musl — fully static linking
- UPX — binary compression for minimal download size
- Property-Based Testing via
proptestfor fuzzing Markdown/XML/noise inputs - CI/CD via GitHub Actions (tests + automatic release)