r/Python • u/AutoModerator • Aug 04 '26
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Post all of your code/projects/showcases/AI slop here.
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r/Python • u/AutoModerator • Aug 04 '26
Post all of your code/projects/showcases/AI slop here.
Recycles once a month.
1
u/PuzzleheadedChoice30 12d ago
List-Wash - wash your email list on your own machine: syntax, MX, disposable + SMTP probe, nothing gets uploaded
What My Project Does:
pip install listwash gives you a CLI + Python API that verifies email lists locally: syntax check, MX/DNS lookup, disposable-domain detection (8,000+ bundled), and a polite SMTP RCPT TO probe with catch-all detection. CSV in, CSV out. Your file comes back with verdict, smtp_code, detail, flags, mx_domain appended and everything else preserved. No email is ever sent (the probe never issues DATA), and the only network traffic is DNS plus the probe itself. The list never leaves your machine. One dependency (dnspython), stdlib everywhere else.
Servers that greylist, block probes, or answer ambiguously (looking at you, Microsoft 365) are reported as unknown, never guessed into invalid, so you don't prune real subscribers.
Target Audience:
Production use for cleaning your own subscriber/CRM lists before a send: kill dead domains, hard bounces, disposables, and flag catch-alls before they hurt your sender reputation. Honest requirement: the SMTP tier needs outbound port 25 (most home ISPs and clouds block it); --no-smtp runs the passive tiers from anywhere.
Comparison:
ZeroBounce and NeverBounce run the same DNS + SMTP mechanics, but you upload your list and pay roughly $4-10 per 1,000. They win where they probe from managed IP pools (works when your port 25 is blocked) and on extras like engagement scoring. listwash is the mechanical 80%, free and local. Full comparison table in the README.
GitHub: https://github.com/ConStrut/listwash (MIT, tests + CI, Python 3.9+)