Signal Plug vs Dux-Soup: Email Discovery vs LinkedIn Automation

Signal Plug vs Dux-Soup: Overview

Signal Plug and Dux-Soup both appear in outbound sales conversations, but they work on different channels.

**Signal Plug** finds verified professional email addresses — the direct inbox channel. Enter a name and company domain, receive an SMTP-verified email with a confidence score.

**Dux-Soup** is a LinkedIn lead generation automation tool. Founded in 2016. It automates LinkedIn activity — connection requests, profile visits, InMail sequences. Direct email contact is not its primary output.

Many teams combine both: LinkedIn automation for awareness and warm connections, then email (discovered via Signal Plug) for direct outreach when the LinkedIn approach doesn't generate a reply.

Feature Comparison

**Signal Plug:** - Find verified B2B email addresses by name + company domain - Live SMTP verification with confidence scores - Contact enrichment (job titles, LinkedIn, social) - 14,000+ company email format database - Bulk search and CSV export - 10 free searches per month — no credit card required

**Dux-Soup:** - LinkedIn automation - Profile visiting - Connection requests - Drip campaigns - CRM integration

These features do not overlap significantly. Signal Plug is for finding a specific person's professional email address. Dux-Soup serves a different function in the workflow.

Pricing Comparison

**Signal Plug Pricing:** - Free Plan: 10 searches per month — no credit card required - Starter: $29/month for 500 searches - Growth: $149/month for 2,000 searches (includes bulk search and CSV export) - Scale: $299/month for 5,000 searches

All plans include real-time SMTP verification, confidence scores, and contact enrichment.

**Dux-Soup Pricing:** Free plan, paid from $14.99/mo

Signal Plug's free tier requires no credit card. Unlike credit-based systems, searches on paid plans don't expire.

Accuracy & Verification Approach

Signal Plug verifies every discovered email via live SMTP check at search time. Results are current — not drawn from a static database. Dux-Soup — LinkedIn only, no email finder, automation risks

When to Choose Signal Plug vs Dux-Soup

**Use Signal Plug when:** Your workflow starts with finding a specific person's verified work email at a target company.

**Consider Dux-Soup when:** You need the capabilities it specifically offers — linkedin automation or profile visiting — that fall outside Signal Plug's scope.

For most outbound teams, both tools address different steps and can be used together rather than as alternatives.

Bottom Line

For direct B2B email discovery — finding and verifying a specific professional's email address — Signal Plug is built for that single job. Dux-Soup covers different ground. The tools complement more than they compete.