Cold Email Marketing with Open-Source Email Extractor

Cold Email Marketing with Open-Source Email Extractor

In this blog post, we will deep-dive into the fascinating world of Cold Email Marketing, exploring its multifaceted strategies, unraveling the do's and don'ts, and introducing you to an exceptional Open-Source tool that simplifies the process of collecting mass-targeted emails.

Related Sources

  • Clauneck: An Open-Source Command Line Tool to Scrape and Extract Emails and Social Network Handles with Targeted SERP Data

  • SerpApi's Google Search API: An Easy-to-use API that provides Real-Time Google Search Results in JSON format

What Cold Email Means?

Cold emailing, a pivotal strategy in digital marketing, stands as the lifeline of many B2B sales campaigns. It's a technique that involves sending unsolicited but well-crafted emails to potential clients or potential customers, primarily for sales, promotional, or networking purposes. Unlike its infamous cousin spam, a good cold email isn't an unsolicited barrage but a carefully personalized note sent to specific individuals or companies. The targets are meticulously chosen based on certain criteria, such as their industry, job title, or interest level in your product/service.

As with crafting a compelling sales pitch, building an effective cold email requires meticulous planning. From devising engaging subject lines, and curating appealing email body content, to ensuring that your email successfully avoids the recipient's spam folder, each step is essential. The best cold email practices are all about addressing a pain point, providing a solution, and adding value to the recipient's life or business, rather than being a pesky interruption.

Is Cold Emailing Illegal?

One of the biggest myths surrounding cold email outreach is the idea that it's illegal. However, in reality, the legality of cold emails hinges on certain key factors and how you execute your outreach email strategy. In most jurisdictions, it's entirely legal to send cold emails for B2B purposes, as long as the email includes an accurate email signature containing contact information, comprising the sender's physical address and phone number. Moreover, the email must offer a clear and conspicuous unsubscribe option, enabling recipients to opt out of future communications with just a click. It is also recommended to use an email checker for verifying valid email addresses to reduce the bounce rate of emails in order to prevent issues with your ESP.

However, things may get a little murky when it comes to scraping emails from social media accounts like LinkedIn or websites. Although it's generally considered legal if these addresses are publicly listed and meant for communication purposes, it's crucial to tread carefully. Every email marketer must vigilantly avoid violating privacy laws or regulations such as the CAN-SPAM Act in the U.S. or GDPR in Europe. Thankfully, CRM systems offer an integrated solution for managing this legal maze, helping to ensure compliance and improve email deliverability.

Does Cold Email Actually Work?

The efficacy of cold outreach campaigns is a hot topic in digital marketing circles, and the simple answer is yes, it can work phenomenally, but with a few caveats with the right kind of automation. The success of a cold email campaign depends heavily on multiple factors. These factors include the quality of your bulk email list, the recipient’s name or company’s name in addressing, a well-crafted opening line giving an intro to your service, the relevance of your message to the recipient, your cold email subject lines, a call to action for a better conversion rate, and the robustness of your follow-up email strategy. Metrics for a cold email strategy such as open rate, reply rate, and conversion rates stand as the cardinal indicators to measure the effectiveness of a cold email campaign.

When implemented right, cold emails can transform into a potent tool for lead generation, enabling salespeople to directly reach the decision-makers, bypassing the usual gatekeepers. To optimize your approach, consider A/B testing different cold email templates, subject lines, and CTAs. For instance, integrating a case study in the email body demonstrating how your product/service resolved a similar problem for another company can bolster your value proposition and amplify your response rate. Also, later in this blog post, we will talk about open-source email extractor software that can increase the precision of your email list to reach a more nuanced audience.

What is Email Scraping?

Email scraping or email extraction is a high-tech process of deploying an email scraper tool or bot to find email addresses and mine them from various online sources. These sources can span from social media platforms, LinkedIn profiles, and websites, to even text files. An efficient email scraper dives deep into HTML and JavaScript codes, scans web pages, and leverages APIs to collate email addresses.

The harvested data is usually stored in a structured format like a CSV or Excel file for effortless access and analysis. However, it's vital to note that while scraping public email addresses for communication or lead-generation purposes can be legal, there are ethical considerations and regulations to be mindful of. Upholding respect for user privacy and adherence to data protection laws should always be paramount when engaging in email scraping activities.

The legality of email scraping may seem dubious, but it primarily depends on the intent behind the act and the method of extraction. If the email addresses are publicly accessible and are collected for legitimate purposes like business prospecting, then it's typically considered legal. Email addresses displayed on websites or public social media accounts are often meant for communication purposes. Hence, employing an email scraper tool to compile these addresses aligns with legal practices. However, adhering to the respective data protection regulations of each country and obtaining consent where necessary is crucial to avoid any potential legal complications.

Why targeting is important in Scraping Emails?

The importance of targeting in email scraping lies in its potency to offer both efficiency and relevance. Efficiency stems from the need to minimize the number of irrelevant or uninterested recipients who are unlikely to engage with your content. By concentrating on a specific target audience or demographic, the volume of emails you scrape may decrease, but the quality of those emails in terms of potential engagement and response enhances dramatically.

Moreover, targeting aids in reducing the likelihood of being classified as spammers. When emails are scraped indiscriminately, there's a higher chance that your sales emails will be dispatched to individuals who have no interest in your content or offerings. These individuals are more likely to mark your emails as spam, activating spam filters which can negatively impact your email deliverability rates and sender reputation. By ensuring that the emails you scrape belong to people likely interested in your offerings, you reduce the risk of your emails being labeled as spam, thereby securing your sender's reputation. This leads to higher open rates, better engagement, and overall improved effectiveness of your email marketing efforts.

How can SerpApi's Google Search API help with targeting?

Although SerpApi's Google Search API is well known for SEO purposes, it can be an influential tool that enhances the process of email scraping by delivering targeted and refined search results. This API allows you to programmatically interact with the Google Search engine, extracting invaluable data from the search results page that can be used to inform and refine your business email scraping strategy.

One way SerpApi's Google Search API can aid with targeted email scraping is by creating a more refined list of websites or companies that align with your business or campaign objectives. For example, if you're running a cold email campaign targeting tech startups, you can use the Google Search API to generate a list of such companies. This list can then be input into your email scraper tool, which will extract the email addresses from these specific websites, ensuring your extracted email list is relevant and targeted.

An Open-Source Email Extractor Tool

Clauneck is a Ruby gem, and a user-friendly command line tool designed to scrape specific information from a series of URLs, either directly provided or fetched from Google search results via SerpApi's Google Search API. Its key feature is to extract email addresses and much more information like social media handles from web pages and to store the results in a CSV file ordered by their domain name.

What Clauneck provides?

The tool looks for high-quality sequences it can find in the targeted website such as email sequences, and then extracts data to a local file in CSV format. If it cannot find any one of the information on a website, it will label it as null. For unknown errors happening in-between (connection errors, encoding errors, etc.) the fields will be filled with as error.

Unlike Google Chrome extensions that need you to visit webpages one by one, Clauneck excels in bringing the list of websites to you by leveraging SerpApi’s Google Search API.

Below is a part of the landing page of SerpApi. You can observe the targeted information in red boxes:

the footer at serpapi

Here's the end result:

WebsiteInformationType of Information


Since SerpApi offers free credits that renew every month, and the user can access a list of free public proxies online, in terms of pricing, this tool is technically a free email finder tool. You may extract data from approximately 10,000 pages (100 results in 1 page, and up to 100 pages) with a free account from SerpApi.

  • For collecting URLs to scrape, one of the following is required:

  • SerpApi API Key: You may Register to Claim Free Credits

  • List of URLs in a text document (The URLs should be Google web cache links that start with

  • For scraping URLs, one of the following is required:

  • List of Proxies in a text document (You may use public proxies. Only HTTP proxies are accepted.)

  • Rotating Proxy IP


You will need to install Ruby on your device. You may take a look at Installing Ruby Documentation.

Then you need to install it from your command line:

$ gem install clauneck

Basic Usage

You can use Clauneck as a command line tool or within your Ruby scripts. Here's the command line usage below:

clauneck --api_key YOUR_SERPAPI_KEY --output "results.csv" --q "site:*.ai AND inurl:/contact OR inurl:/contact-us" --proxy "proxies.txt"

The search query in the tutorial: "site:*.ai AND inurl:/contact OR inurl:/contact-us" will search for websites ending with .ai and at /contact or /contact-us paths. You may use more intricate search commands to target more specific groups in alignment with your needs.


I am grateful to the reader for their attention. I hope this blog post and the open-source email address extractor tool can bring ease to your marketing campaigns. Feel free to use it in your integrations, or plugins. If you want to know more about the tool's capabilities or would like to participate in its improvement, you may visit