6 Cold Email Tools Proven to Boost Response Rates for Agencies

Getting responses when you’re working at scale can be like pulling teeth, especially for agencies. No one likes to feel like they’re just a data point in some faceless marketing campaign, and they tend not to engage with your outreach when they do. People need to feel personally targeted to respond, and you need their responses to produce results. So what’s an agency rep to do?

Fortunately, you don’t have to agonize over how to get more responses at scale. This article highlights six powerful cold email tools tested and trusted with boosting response rates with next-level personalization and other special features. 

1. Instantly

With Instantly, boosting response rates is as simple as clicking a few buttons. The platform has extensive AI integrations that allow users to research leads and generate personalized email copy at scale. It does this with AI Copilot, a ChatGPT-like outreach assistant that can automate the entire process of finding and sending hyper-effective, personalized outreach to the right prospects, thanks to its WARP mode feature. Instantly also offers unlimited email accounts and unlimited warmup to ensure deliverability, and includes a comprehensive inbox placement tool to keep you out of the spam folder. 

Feature Highlights

• AI content writer: Use Instantly’s proprietary AI content writer to produce effective, highly personalized email copy. 

• Copilot tasks: Set up the AI Copilot to automate recurring tasks on a daily, weekly, or monthly basis. 

• Copilot memory: Let Copilot learn from your website or campaign materials to customize your outreach further.

• AI spintax: Get human-like variation in word choice and sentence structure for your email copy. 

• AI spam checker: Flag and replace words and phrases that frequently trigger automated spam filters. 

Pros 

• Accessible, user-friendly interface.

• Automates A/Z testing to sharpen email copy over time. 

• Massive B2B database with more than 450 million verified leads. 

• Use the slow ramp feature to ensure that automated messages are sent at human-like intervals.

Cons

• Instantly’s Copilot feature works best when users have a website or existing outreach material for the AI to analyze. 

2. SmartReach 

SmartReach takes a multichannel approach to cold email, enabling users to reach out to prospects across multiple platforms. Paired with its deep AI-powered personalization, this makes each lead feel more uniquely targeted and increases the response rate. It also has a CRM tool built in for managing prospects. 

Feature Highlights

• Hyperpersonalization: Analyze your Ideal Customer Profile and use AI to generate personalized cold outreach that follows best practices. 

• Holiday calendar: Stop outreach on days where it might be considered inappropriate or is likely to be ignored. 

• Direct/Indirect reply detection: Track lead responses across multiple email addresses to keep personalization across both personal and business accounts. 

Pros 

• Automatically halt AI-powered outreach when manually responding to or messaging leads.

• Offers more multichannel outreach with cold calling features.

Cons

• Limited CRM features. 

• Requires high-tier plans for personalization features. 

3. Mailshake 

Mailshake’s dedicated AI email writer, SHAKEspeare, has a range of built-in features that help improve response rates. It ensures variation by generating three different versions of your email copy based on prompts, and then personalizes each message for individual leads before it goes out. 

Feature Highlights

• Text variations: Update parts of your email copy to improve them with a simple highlight using SHAKEspeare.

• Follow-ups: Have AI automatically respond to leads to keep engagement and responses flowing. 

• Mail merge: Send outreach to a related group of leads and automate customizing it for each recipient.   

Pros 

• User interface allows switching between automated and manual responses. 

• Unlimited email verification to ensure deliverability.

Cons

• A multichannel setup means users running cold email outreach pay for unnecessary features. 

• Not cost-effective for single-channel cold email outreach campaigns.

4. Reply

Reply is an AI-focused platform built for sales, and as such, it has a strong focus on finding the right leads that fit your ideal customer profile. This means that all your outreach goes out to people who you already understand their needs, and its AI features help you customize emails with personal information beyond pain points.

Feature Highlights

• Smart audience selections: Use AI-powered prospecting tools that find leads that fit your ideal customer profile for easier personalization. 

• AI variables: Generate email copy that automatically fills in personal information for each lead. 

• AI-generated sequences: Create sequences for each lead based on AI-powered profiling and response behaviour.   

Pros 

• Users can switch between automated responses and AI-augmented manual responses. 

• Multichannel outreach sequencing across email, LinkedIn, and calls.

Cons

• The pricing is very expensive compared to competitors offering the same features.

• Modular design is complicated, requiring users to piece together multiple add-ons for full functionality.

5. Klenty

Klenty’s outbound automation is purpose-built to help you build rapport with your leads, using AI to personalize every email and automate the repetitive tasks that take time away from getting to know your prospects. Thanks to this approach, Klenty ensures response rates increase over time. 

Feature Highlights

• AI account research: Use 150+ data sources to enrich leads for better personalization and higher response rates. 

• Agentic cadences: Leverage AI to research individual leads and follow up with automated personalized emails. 

• AI account signals: Determine the best times to reach out to each lead and schedule outreach accordingly. 

Pros 

• Payment structures that favor long-term outreach campaigns.

• Offers instant feature personalization based

Cons

• Requires higher-tier plans for full personalization features. 

• Doesn’t offer monthly payment options. 

6. Lavender

Lavender is a dedicated email intelligence platform designed specifically to fix your email copy and get you more responses. It scores and optimizes existing email copy, as well as creates new, effective first drafts for your campaign. Lavender also automatically optimizes emails for mobile viewers to encourage on-the-go responses.

Feature Highlights

• ChatGPT add-on: Use Lavender’s add-on to access ChatGPT directly from your email interface with any ESP. 

• AI email builder: Generate personalized email copy with AI from user-defined bullet lists in natural language.  

• GIFs: Add GIFs to your email copy and add some levity to your outreach without leaving your email interface.

Pros 

• Works across all email service providers and web interfaces

• Free premium passes for students, job seekers, and entrepreneurs looking for funding.

Cons

• Certain payment tiers can’t access integrations. 

• Doesn’t offer many features beyond email personalization. 

Final Thoughts

Whether it's dedicated tools like Lavender or AI-driven platforms like Reply and Klenty, all these tools excel at one or two ways to improve response rates. However, only one offers everything you need to maximize your ROI when reaching out to prospects. 

Instantly uses proprietary AI tools to combine comprehensive personalization, unlimited deliverability, and industry-leading inbox placement—instantly boosting response rates for your agency’s campaigns. If you’re looking for a solid all-in-one cold email tool that’s guaranteed to get leads intrigued and responding, Instantly is the right pick for you.