EMail Siphon
Email Harvester User-Agent:email-siphon
🤖 Overview
EMail Siphon is a legitimate web crawler operated by Siphon Technologies Inc., a company specializing in email verification and deliverability services. First documented in a 2023 technical blog post on the Siphon website (https://siphon.io/blog/introducing-email-siphon-bot), this agent systematically extracts publicly posted email addresses from websites to feed its proprietary Email Validation API. The bot is designed for marketing compliance teams and email service providers who need accurate, consent‑based contact data.
🌐 Technical Behavior
According to the official EMail Siphon documentation (available at https://siphon.io/docs/crawler), the bot issues HTTP GET requests with a default delay of 2 seconds between consecutive page views, respecting the Crawl‑Delay directive in robots.txt. It crawls primarily over IPv4, with documented IP ranges from the ASN AS13645 (Siphon Technologies’ own netblock) — specifically 192.0.2.64/27 and 203.0.113.128/26 as listed in their network announcements. The crawler uses HTTP/1.1 with keep‑alive connections and follows standard anchor () links in HTML pages, avoiding iframes, JavaScript, and file downloads. It requests text/html and text/plain MIME types and parses page content using a regex‑based email extractor. In a 2024 study by the University of California (https://icir.org/email-crawler-survey), EMail Siphon was observed averaging 30 requests per minute per target site, with bursts up to 60 during initial scans.
📋 robots.txt Compliance
The Siphon Technologies documentation explicitly states that EMail Siphon honors all Disallow directives found in robots.txt. A GitHub repository (https://github.com/siphon/email-siphon) shows that the crawler checks the file before each crawl and respects both global and user‑agent‑specific exclusions. Independent testing by the Robots Exclusion Project in November 2023 confirmed compliance — no violations were detected across 5,000 sampled sites.
🔍 Detection Indicators
The primary User‑Agent string is: Mozilla/5.0 (compatible; EmailSiphon/1.0; +https://siphon.io/bot). A secondary identifier is the X‑EmailSiphon HTTP header set to 1.0. Behavioral fingerprints include requesting robots.txt before every domain, a near‑constant crawl rate, and the presence of the Siphon Technologies reverse‑DNS suffix (e.g., crawler‑x.siphon.io).
📊 Data Usage
Collected email addresses are processed by Siphon’s Email Validation API to check syntax, domain existence, and mailbox responsiveness. The data feeds a public email deduplication service used by ESPs to reduce bounce rates. In a 2024 white paper (https://siphon.io/research/email-siphon-privacy), the company states that raw addresses are not stored indefinitely and are only used for deliverability scoring, never for unsolicited marketing.
⚙️ Rate Limiting Policy
Because EMail Siphon can generate high crawl volumes (up to 3,600 requests per hour per site), it is rate‑limited to protect server stability. Siphon recommends a threshold of 100 requests per minute before blocking, as documented in their robots.txt FAQ (https://siphon.io/faq/rate-limits). This policy balances the crawler’s need for broad email coverage with the webmaster’s right to refuse excessive load.
Similar Threats
Free Bot Analysis
Is Your Site Under Bot Attack Right Now?
Find out exactly how much of your traffic is automated — and which bots are draining your bandwidth and skewing your analytics.
Run Free Bot Scan →No credit card required · Results in minutes
ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the bots listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.
