If you're running outreach for clients in 2025, your tools matter more than ever. Agency life means juggling multiple campaigns, customizing messages at scale, and proving ROI - all without burning your team out. That’s why having the right outreach tool stack is non-negotiable.

In this post, we’ll break down the best outreach tools for agencies today: from cold email software and multichannel automation to CRMs and personalization engines. Whether you're building your agency sales outreach software stack from scratch or optimizing your current tech, this guide has you covered.

Why Agencies Need a Solid Outreach Stack

Outreach is no longer just about sending emails. It's about building sequences that combine email, LinkedIn, calls, and personalized touches. The best outreach tools for agencies are built to handle:

• High-volume prospecting across multiple client accounts

• Smart personalization with minimal manual effort

• Easy campaign tracking and reporting

• CRM and email stack integration

• Team collaboration and task assignment

Let’s look at the tools making this possible.

1. Apollo.io – For Lead Data, Outreach, and CRM Sync

Apollo is a powerhouse for outbound agencies. It combines a robust B2B contact database with sales engagement features.

• Why agencies love it: All-in-one lead generation and outreach with easy CRM integration.

• Key features: Email automation, lead scoring, contact enrichment, email analytics

• Great for: Agencies that need scalable cold outreach software for B2B clients

2. Clay – For Hyper-Personalized Prospecting at Scale

Clay is an agency favorite in 2025. It pulls data from dozens of sources and automates personalized outreach using AI.

• Why agencies love it: Flexible and built for dynamic outreach workflows

• Key features: Live data enrichment, AI personalization, drag-and-drop automations

• Great for: Complex personalization at scale for cold outreach campaigns

3. Lemlist – For Visual Personalization and Multichannel Outreach

Lemlist shines when it comes to creative cold email campaigns that get replies.

• Why agencies love it: Video and image personalization, plus multichannel support

• Key features: Email builder, LinkedIn automation, call sequences

• Great for: Marketing agencies and SDR teams wanting more than just email

4. Smartlead.ai – For Deliverability and Volume

If you need to send high volumes of cold emails without deliverability issues, Smartlead.ai is a go-to.

• Why agencies love it: Inbox rotation, unlimited sender accounts, clean UI

• Key features: Deliverability tools, A/B testing, campaign-level metrics

• Great for: SDR tool stack for agencies scaling fast

5. HubSpot Sales Hub – CRM + Outreach in One

Agencies need CRM, but not just for contact storage. HubSpot’s Sales Hub offers automation, tracking, and reporting in one platform.

• Why agencies love it: Powerful outreach CRM for agencies already using HubSpot

• Key features: Sequences, tasks, deal pipeline, email templates

• Great for: Client management and internal agency sales

6. Waalaxy – For LinkedIn Automation at Scale

When email isn’t enough, Waalaxy helps you tap into LinkedIn outreach without manual work.

• Why agencies love it: Multichannel sequences including LinkedIn and email

• Key features: Prospect syncing, personalized invites, campaign dashboards

• Great for: Agencies targeting professionals or niche industries on LinkedIn

7. Folk CRM – Lightweight CRM Designed for Agencies

Folk is a modern CRM built with collaboration in mind. It’s perfect for smaller agencies that don’t want bulky software.

• Why agencies love it: Simplicity, automation, and team-friendly features

• Key features: Smart contact lists, reminders, integrations

• Great for: Client onboarding, relationship management, and team task tracking

Outreach Stack Comparison: How They Work Together

Here’s how a full-stack might look for your agency in 2025:

• Prospecting & Data: Apollo.io, Clay

• Personalization Engine: Clay, Lemlist

• Email & LinkedIn Automation: Smartlead.ai, Lemlist, Waalaxy

• CRM + Outreach Hub: HubSpot, Folk

• Reporting & Optimization: All tools offer dashboards, but use Clay or HubSpot for deeper metrics

The best tech stack for outbound sales isn’t just about tools—it’s about integration. Look for outreach tool integrations with Slack, Zapier, Google Sheets, and your CRM to ensure everything works together.

Choosing the Right Tools for Your Agency

Before you pick your tech stack, ask:

• Do we run outreach for clients or internal growth?

• How many clients do we manage campaigns for?

• Do we prioritize volume or personalization?

• Do we need multichannel capabilities or just email?

• What’s our existing CRM and email setup?

Your answers will determine whether you need a lean setup or a full-scale multichannel outreach platform.

Final Thoughts

The best outreach tools for agencies in 2025 aren’t one-size-fits-all. Your ideal stack depends on your campaign style, client volume, and how personalized your approach needs to be.

But with tools like Apollo, Clay, Lemlist, Smartlead, and Waalaxy, you can build a high-performing outreach engine that delivers results and scales with your agency.

Want a smarter way to run your agency's outreach? Start with a lean, integrated tech stack and scale from there.