Cold email still works for agencies, but only when it actually reaches inboxes. According to recent data, cold emails can achieve response rates between 1-5%, with open rates climbing as high as 60% when done right. For agencies managing multiple clients, though, the stakes are different.
Instead of one campaign, agencies run dozens at once across different industries. Each client has different goals, different messaging, and different success metrics. If deliverability or reply rates drop, clients blame the agency. The pressure is on to book meetings that justify your fees while managing tools that scale without costing too much.
So, in this post, we’ve compiled a list of six cold outreach platforms designed to handle agency demands: pricing that scales with growth, deliverability features that protect client domains, and tools that turn volume into booked meetings.
1. Instantly
Instantly automates every step of your outreach, from sourcing leads and creating multichannel sequences to improving deliverability and monitoring what’s working.
The lead finder pulls from a database of 450 million B2B contacts, so you can build targeted lists in the same platform. You can write sequences from scratch or use the platform’s AI writer to generate personalized variants that prevent emails from sounding identical. And if you need to reach people across different channels,Instantly also supports LinkedIn and SMS in the same workflow.
On the deliverability side, automated email warmup runs across a network of 4.2 million accounts to build sender reputation before campaigns go live. There’s also inbox placement testing that shows where emails land (primary, promotions, or spam), allowing you to fix issues before clients notice.
The dashboard consolidates replies from all client accounts into one inbox with AI filters that sort responses by sentiment, so you can see which replies need immediate attention and which ones can wait. Each client gets their own workspace to keep campaign data separate while you manage everything from a single login.
The pricing model is perfect for agencies that need to scale without multiplying costs. Most platforms charge per user or per email account, which gets expensive when you're managing multiple clients. Instantly, on the other hand, charges for sending capacity while including unlimited email accounts. This means that your base cost stays the same, regardless of whether you're managing five clients or fifteen.
2. Apollo
Like Instantly, Apollo.io combines prospecting and outreach in a single system. The platform gives you access to a database of 270 million contacts that you can filter by job title, company size, industry, tech stack, revenue signals, and buying intent. Once you've built a list, you can push contacts directly into campaigns without exporting and importing between tools.
The Chrome extension makes LinkedIn prospecting faster by pulling contact information from profiles and company pages, then adding them with one click. Apollo lets you coordinate email and call tasks in the same workflow, so your team can manage touches across channels. The platform also recently added email warmup and inbox ramp features, which help new sending accounts build reputation before going live.
The AI email writer helps speed up content creation by generating different versions of your messaging, and because Apollo integrates natively with Salesforce, HubSpot, and Pipedrive, deal updates sync automatically.
The downside is how Apollo handles pricing and account limits. You pay per user seat, and each seat restricts how many email accounts you can connect. Basic and Professional plans give you one inbox per user, while the Organization tier bumps that to 15. If your agency model involves running separate domains for each client, this means either upgrading to expensive tiers or adding more user seats just to access more inboxes.
3. Klenty
Klenty’s system is built around three core tools: Prospect IQ for building lists, Sales Engagement for running campaigns, and Schedule IQ for meeting coordination.
Klenty gives agencies more personalization depth than most platforms. Merge Fields let you customize content by prospect type, while Liquid Templates use dynamic formulas to adjust messaging based on when emails are opened. In addition, the AI writer scans prospect websites and LinkedIn profiles to generate personalized openers, problem statements, and CTAs automatically.
The platform supports multichannel cadences that combine emails, calls, LinkedIn tasks, SMS, and WhatsApp messages in unified workflows. For agencies managing consistent outreach across channels, this keeps client campaigns coordinated without having to subscribe to multiple platforms and tools.
Klenty also handles deliverability through email validation to reduce bounce rates, sending controls that limit daily volume and stagger sends irregularly, and insights that show inbox placement percentages across email providers while scoring messages for spam factors.
However, like all platforms, Klenty comes with some downsides. The interface requires more time to master, and pricing runs higher than simpler platforms, creating barriers for smaller teams or tighter budgets.
4. Lemlist
Lemlist stands out as a cold outreach tool agencies use to boost meeting bookings through personalized communication at scale. Its approach helps teams send messages that feel more human, improving response rates while supporting consistent outreach. Agencies rely on it to streamline campaigns, maintain momentum, and stay visible to high-value prospects.
Agencies value Lemlist because it reinforces brand presence through tailored messaging that resonates with prospects. Its structured outreach process helps maintain steady engagement across multiple channels, supporting campaigns that aim to convert conversations into scheduled meetings. By enabling repetition with personalization, it helps teams nurture leads more effectively throughout their outreach pipeline.
Within the lineup of seven cold outreach tools agencies often use, Lemlist contributes by supporting campaigns designed to spark replies and encourage meeting requests. Agencies adopt it to help keep prospects engaged, ensure follow-ups occur consistently, and elevate the overall outreach experience, ultimately increasing opportunities for booked calls and business growth.
5. Saleshandy
Saleshandy includes a dedicated agency portal where you can manage all client campaigns from one central dashboard. You can onboard unlimited clients, team members, and email accounts without additional fees, which keeps costs flat as you scale.
Saleshandy spreads sending across accounts using sender rotation, which helps maintain deliverability even at high volume. The platform supports email personalization through dynamic placeholders, so you can customize subject lines, opening lines, and other elements without manually rewriting each message. Automated follow-ups run based on conditions you set, making it easier to stay in front of leads without tracking every touchpoint manually.
The platform integrates with Pipedrive, HubSpot, Salesforce, Zoho CRM, and Zapier to keep workflows connected across client tech stacks. The centralized management means you're not switching between different logins or interfaces to monitor campaign performance.
If you run into limitations, it'll be around plan caps on active prospects, monthly sends, and per-sequence sender rotation. Email warmup also runs through TrulyInbox, a partner integration rather than a native feature.
6. Mailshake
Mailshake makes it easy to manage cold email, calling, and LinkedIn outreach for multiple clients without paying per seat. The platform includes unlimited email warmup, inbox rotation, and validation as standard features, which helps agencies protect client domains while scaling campaigns.
Personalization works through dynamic fields that adjust messaging based on prospect data. You can run A/B tests on subject lines, copy, and CTAs to see what drives replies, then use those insights across client campaigns. Analytics focus on what matters for client reporting: reply rates, meetings booked, and engagement over time.
Mailshake integrates with Salesforce, HubSpot, and Pipedrive to keep client data synced across systems. The built-in dialer and LinkedIn automation run alongside email sequences, which means you can coordinate cold calls and connection requests without managing separate tools.
However, Mailshake's interface hasn't kept pace with newer competitors, and if you need complex workflow automation, you'll find the platform lacking compared to enterprise-level tools.
Final Thoughts
Cold outreach only scales when the infrastructure behind it works. Most agencies run into trouble as they grow because their platform charges per seat, limits accounts, or can’t handle high volume.
The right platform lets you grow without having to worry about those issues. With the right setup, campaigns stay organized, domains stay healthy, and reporting shows clients actual results. The result is more meetings booked while keeping costs flat and sender reputation intact.
If you're paying more every time you add a client, try Instantly and see what flat pricing with unlimited accounts does for your bottom line.
