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You’ve got a list of people in a target segment – time to start generating some interest – let’s start with cold e-mail – always a classic. For cold email outreach we’re going to build and design and infrastructure that could scale up to 25,000 contacts. That doesn’t mean we’re going to immediately scale to that number. It does mean we’re going to plan and build to get to that scale or beyond, though.

This guide walks you through each step to ensure your campaign is effective and doesn’t get you sued or marked as spam. It’ll cover everything from setting up domains and inboxes to warming them up, managing the list, optimizing deliverability, crafting a sending cadence, leveraging LLMs to get compelling e-mail copy, testing, tracking, and, as noted, staying within legal bounds. This guide pulls together what I’ve learned from other B2B SaaS marketers.

This guide assume that you’ve already built out a *very* targeted list from your Target Segments / ICP and that you are crystal clear on the Personas you are selling to.

Domain and Inbox Setup

Use Alternate Domains to Protect Your Primary Domain

If you send outbound e-mails from your company’s primary domain you’re almost guaranteed to have it marked as spam. Instead, we’re going to register a series of alternate but similar domain names. For example, if your primary domain is YourCompany.com, you might register YourCompany.co, YourCompany.net, or variations like TryYourCompany.com. Using multiple domain variations is a proven strategy to spread out sending volume and dodge spam filters. It mitigates the risk of your main corporate domain being blacklisted or flagged for spam.

Mailbox Setup and Hosting

You have many options for hosting email accounts but for our scale we’re going to use a combination of accounts SendGrid (To Send) and Google Workspace (To Receive). We’ll then use Instantly.ai on top of this to help manage the campaign. In practice, this means replies land in the Gmail inbox, but outgoing mail goes through SendGrid’s servers.

Set Up DNS Records (SPF, DKIM, DMARC)

If you are using Instantly to setup your domains you can skip this step – they’ll do it for you. If you’re using a third party service, immediately, after getting your domains, configure the DNS for proper email authentication:

Other Setup Items

Why is all this important? First, it ensures the messages we’re sending have a chance of getting in front of the people we’re sending to. That’s deliverability. Second, by setting up separate, real domains and properly configuring authentication, we protect our primary domain’s reputation. Now that the infrastructure is in place, let’s warm up those domains and inboxes before the big send.

Warming Up Your Domains and Inboxes

Before blasting out thousands of emails, you need to warm up your new domains and email accounts. Warming up means gradually establishing a positive sending reputation by sending a low volume of emails that get good engagement. Instantly.ai provides an automated warm-up feature that is extremely useful for this process.

By properly warming up, you establish a solid sender reputation for your new domains before you ever send a single cold sales pitch. This warm-up period might feel like a slow start, but it pays off by drastically improving inbox placement when you launch the full campaign.

Integrating SendGrid with Instantly

With your domains warmed up and ready, the next step is to configure Instantly and SendGrid so they work together seamlessly. Big picture we want to use SendGrid’s robust email sending infrastructure (think: ability to send lots of e-mails) while leveraging Instantly’s sequencing and deliverability features (think: sending smart e-mails on that infrastructure). Here’s how to set it up:

  1. Set Up SendGrid (Sender Authentication): In your SendGrid account, go to Settings > Sender Authentication and authenticate your domain. SendGrid will guide you through adding DNS records (usually CNAMEs) to verify your domain and set up DKIM signing. Complete this step for each sending domain. This ensures emails sent via SendGrid on behalf of your domain pass SPF and DKIM checks. Also, retrieve your SendGrid SMTP credentials (SMTP server, port, and API key or username/password). Typically:
    • SMTP Host: smtp.sendgrid.net
    • SMTP Port: 587 (TLS) or 465 (SSL)
    • Username: apikey (literally this word for SendGrid)
    • Password: your actual SendGrid API key (you’ll generate this in the API Keys section).
  2. Prepare an IMAP Email Account: Instantly requires both sending (SMTP) and receiving (IMAP) access for an email account. If you are using SendGrid for SMTP, you still need an IMAP inbox to connect. Our approach is to use Google Workspace for IMAP. This ensures we have “real” Google Workspace domains backing any outbound inboxes we use..
    • Note: You’ll need to enable IMAP in the Gmail settings and create an App Password (if you have 2FA enabled) to use for login.
  3. Connect Accounts in Instantly: In Instantly, navigate to Email Accounts > Add New and choose to connect via IMAP/SMTP. Instantly will ask for:
    • Email Address: Enter the email address that you want to send from (e.g., [email protected]). This will be the “From” address on your cold emails.
    • IMAP Settings: Enter the IMAP host (e.g., imap.gmail.com for Gmail) and port (993 for secure IMAP), and the login credentials for your receiving account. For Gmail IMAP, the username is your Gmail address, and password is the App Password from step 2.
    • SMTP Settings: Enter SendGrid’s SMTP details. As noted: SMTP Host = smtp.sendgrid.net, Port = 587. Username = apikey (literally that word) and Password = your SendGrid API key. This config tells Instantly to send outbound emails through SendGrid.
    • Submit and Test: After entering these, click to connect. Instantly will test the connection. A successful integration means Instantly can now send emails via SendGrid and read incoming emails via the IMAP account.
  4. Repeat for All Sending Accounts: You’re going to have lots of inboxes – typically five per domain. You’ll likely just use one SendGrid API key for all or you can separate them out and do one SendGrid account per odmain. The key thing is each “From” address domain is authenticated in SendGrid. Similarly each account in Instantly will need a unique IMAP inbox (or at least a separate email address). Note that these need to be real, separate inboxes so we have distinct options.
  5. Configure Sending Calendar and Throttling in Instantly: In Instantly’s settings for each account, set up parameters to spread out your sending:
    • Define the daily sending limit per inbox (for example, “max 50 emails per day per account” to start, then you might increase later).
    • Set the sending schedule – e.g., weekdays only, between 8:00 AM and 5:00 PM of the recipient’s time zone. Instantly will auto-detect time zones based on email domain. It’s wise to send during normal business hours of your targets for higher open rates.
    • Stagger send times: Instantly will randomize send times within your window so that emails go out sporadically rather than back-to-back. This mimics natural sending and avoids volume spikes. For example, if you schedule 50 emails over 8 hours, it might send roughly 6-7 per hour rather than all 50 at once.
  6. Setup Tracking: As appropriate based on your needs you can configure a custom tracking domain for opens/clicks. Since these are cold e-mails, however, we recommend you disable open tracking in your cold email tool to eliminate the open-tracking pixel. This keeps the e-mails as “plain text” as possible which generally helps with open rates and deliverability. The catch is open metrics are useful to gauge performance so it’s a trade-off. If you do want tracking setup a custom domain for it so it’s less blatantly from a marketing service.
  7. Test Everything: Before sending to your 25,000 leads, do a thorough test. Create a small campaign to send a test email to a few of your own addresses and test across different email providers: Gmail, Outlook, Yahoo, etc. As part of the test ensure:
    • The emails are actually sending via SendGrid (check SendGrid’s dashboard for activity).
    • The email content looks correct (no formatting issues).
    • SPF/DKIM are passing on the received test emails (check the headers in Gmail by viewing “Original Message” – you should see spf=pass and dkim=pass).
    • The unsubscribe link works.
    • Replies to the test go into the IMAP inbox and Instantly correctly shows the email as replied.

If tests reveal any problems (e.g., emails landing in spam, or not sending at all), troubleshoot. Common fixes include correcting DNS records, adjusting content (more later), or tweaking SMTP/IMAP settings.

Contact List Management

This guide assumes that you have a well defined and clearly targeted list that you are sending to. It assume each person in that list is tagged to a very specific Buying Persona and we’re very clear about why that person would care about our outreach.

So while we won’t cover list building here in depth a few key things we are assuming about your list:

The Joys of Email Deliverability (SPF, DKIM, Throttling, and More)

You must proactively optimize for deliverability throughout the campaign. Hitting the inbox (and not the spam folder) is the goal. Here are key deliverability techniques and best practices:

In summary, treat deliverability as an ongoing priority. Authenticate everything, send thoughtfully, and watch like a hawk. When done right, your emails have the best chance to land in the coveted inbox, ready to be opened by your busy executive prospects.

Advertising Air Cover

Before sending outbound emails to people who have never heard of your brand, we prefer to create familiarity through targeted advertising. We think of this approach as “advertising air cover” which, ideally, takes it from completely cold outreach to lukewarm outreach. The goal is to build recognition and trust by putting valuable, relevant content in front of your audience before the first email lands in their inbox.

Since you already have a detailed list of your target prospects, the next step is selecting the right thought leadership content to show them. This content should reflect the challenges, interests, and priorities of your audience. Think along the lines of expert insights, industry trends, how-to guides, success stories, or unique points of view that align with what your brand stands for. The aim is not to sell immediately, but to educate and create a sense of relevance and authority.

With the content strategy defined, you can begin executing ad campaigns across social platforms that allow precise list targeting. Networks like Facebook (via Meta), LinkedIn, and Twitter offer tools to upload your contact list and serve ads directly to those individuals. Tools such as MetaMatch can enhance this process by improving match rates.

The result is that by the time your prospects receive your outreach email, they’ve already encountered your brand, seen useful content from you, and started to associate your name with value. Since the objective here is to build trust and reputation we like to provide ungated, truly free content here. I.e. don’t put that content behind a registration form. That’s not our objective. Our objective is to get people to engage with something compelling from our company and there’s no better way to do that than “free”.

Designing the Sequence and Cadence

With infrastructure and deliverability squared away, focus on your outreach strategy: the sequence of emails, their content, and the timing/cadence. A thoughtful sequence will give you actual response rates. A sequence of one good e-mail and the rest bullshit “did you see that last e-mail” tags will condemn you to the spam folders. Basic concepts:

A single e-mail isn’t going to work. Cold leads require a few touches – way more than we’re even going to put into place here. Remember 95% of these accounts are not in the market. They aren’t looking to buy your product right now. We’re trying to get on their radar so that when they’re in consideration phase they start to think about us.

Industry research shows many B2B deals or replies happen only after multiple follow-ups. Plan a sequence of emails that gradually adds value or reminds the prospect of why you’re useful to them in their professional life. For example:

Initial Outreach

A personalized introduction explaining the reason for reaching out, being specific about a key pain point they have that provides relevance to the outreach and a crystal clear call-to-action. The call to action is ideally something that immediately provides value to their life and is interesting to them. For example: I took the liberty of building out a profile for your organization and granting you access to it in our cool SaaS solution, you can find that here: [URL]

Second Outreach – A Different, Valuable Thing

Sent ~3-4 days after the first if no reply. Some guides will tell you that this should be a gentle reminder of the form “Just bumping this to your attention, I know how busy you are…”. I fucking hate those e-mail. So much. So deeply. All they do is further waste the receivers mind and move your further away from being a value added vendor. You wasted my time with my first e-mail and now all your doing is reminding me that you wasted my time. It provides o additional value or relevance to the customer. We’ve done nothing to demonstrate value or move the ball forward.

Instead, open with a concise subject line that hints at a new, proprietary insight you’ve uncovered about the prospect’s business. In the text provide a note on additional research you’ve done—highlighting one sharp, data-backed observation about a recent initiative at their company or market trend. You explain how this specific finding directly ties to a capability of your product that can address the challenge or opportunity you’ve identified, illustrating the benefit in concrete terms (for example, time saved or costs cut.

The second paragraph reinforces credibility by mentioning a similar company that achieved measurable results using that same feature, serving as concise social proof. It then makes a low-commitment invitation—offering to send a one-pager or hop on a 10-minute call to explore the idea further—emphasizing that the next step is optional and easy. I always like including some personally relevant note as a P.S. that connects you, the sender, to what you know about them, the recipient, from public research.

Third Outreach – Competitive Dynamics

A week after the second outreach I like to shift a little bit to the market the customer is in. Here we’re again demonstrating that we’ve done our homework and our researching their space. The email opens with a subject line referencing one of their key competitors—something like “[Competitor] – [Solution Use Case] Analysis.” It briefly reminds them that you’ve been tracking the space and positions this as new intelligence rather than another generic follow-up. You then summarize the competitor’s initiative as it relates to your solution. You then provide a free option for the prospect to start to close that competitive gap. Example: “I took the liberty of doing a similar analysis on your site and am including a link to it here: [URL]”. The key thing is that the prospect has a low friction way to understand the competitive dynamic and a path to close that gap that goes through us.

In the second paragraph, you do something similar to e-mail two: build credibility by mentioning a similar customer who leveraged your solution to neutralize a competitive threat and gained measurable ground (for example, winning two new enterprise deals within a quarter). You then offer a simple, low-friction next step—such as sharing a brief competitive playbook or hopping on a 10-minute call to outline how they could deploy the same strategy. Finally, note an optional P.S. that points to a concise industry snapshot or benchmark report comparing leading players’ performance, reinforcing that you understand the broader market context and are here to keep them informed.

Fourth Outreach – Insight Hub

Lead with a subject line that calls out the fact you’ve built something just for them—something like “[Prospect Company] – [Solution Space] Research Hub.” The opening acknowledges you’ve been researching their company and wanted to go beyond words on a page, so you designed a private micro-website that aggregates all the relevant analysis, benchmarks, and case studies we’ve gathered on their specific market challenges.

The body of the email highlights what they’ll find on that site: a personally curated set of content that will help them research and understand the solution space for what we offer. This site will get built out automatically using Air Traffic Control and automatically updated as the prospect interacts with more content. You then provide a personalized link and invite them to explore at their convenience, offering to walk them through it in a brief call or to expand the site with any additional data points they’d like to see. This approach turns the outreach into an interactive experience—showing you’ve invested the time to create real, hands-on value.

Fifth Outreach – Breakup E-mail?

Typically these are called “break-up emails” in most cadences. I hate that as well. To breakup you had to have a relationship with a person. You have no relationship with this prospect. We can’t breakup with someone we didn’t have a relationship with.

I like to just call that out. The email opens by acknowledging you haven’t heard back and that best practice here is to send a “breakup” note. I think that’s ridiculous as we don’t have a relationship and clearly haven’t done enough to earn your attention. Instead, recap the research we’ve done on the company to date as it relates to our solution: the initial introduction to your solution, the tailored industry insight you shared, the competitive intelligence on their rivals, the personalized ROI snapshot, and the custom content hub you built just for them. This summary underscores all the value you’ve invested in understanding their business and their market without making them feel guilty for not responding.

In the second paragraph, describe that you are and shall remain at their disposal it they have some interest in your solution in the future. Note that their site will remain live and updated for the next year —no strings attached— and that we’ll update it from time to time as we see their competitors move or have other relevant industry research that’s useful to them. Emphasize that you’re always available for a quick chat or to provide more reserach if they decide to dive deeper. Finally, you thank them for their time and let them know you’d welcome any opportunity to reconnect whenever they’re ready.

Cadence Notes

AI Writing Notes

We’re going to use AI to write all the messages above. We tend to do this with our own custom LLM prompts that are backed by the social graph engine that we’ve built in Creso.ai. Here’s what we provide as context for the prompt:

We’re than going to provide very concise message authoring instructions for the AI. These define the core objective of the e-mail, specify the desired structure and length (example two concise paragraphs), identify the key points or data that must be emphasized, and include any precomputed URLs, links, or attachments that should appear. It may also outline the tone to strike and the specific call-to-action you want inserted, ensuring each message aligns precisely with your outreach goals.

The common approach you’ll see in most cadence is a template‐driven approach that lightly uses AI. It basically drops a few AI‐written snippets into fixed frames in the e-mails. In our experience that produces emails that feel patched together and generic. Instead we want an end‐to‐end prompt method that more accurately models who people write e-mails to other people. They don’t write as templates. They write an entire message, weaving in all the prospect’s context, research insights, and personalized calls to action. By generating the full email rather than isolated fragments, you avoid awkward transitions and repetitive boilerplate. That should deliver you a cohesive narrative that reads as a tailored, human‐crafted message instead of a formulaic template.

A Note On Subject Lines

Subject lines are crucial for open rates. I like these to be catchy and specific to the prospect’s company or role. Since we have a ton of context in the prompt we’re providing to the LLM have the LLM write up a catchy 3-5 word subject line that defines the relevance of the e-mail to the prospect. In all scenarios we want to avoid things that are obviously template driven “Quick question, {FirstName}” or “{FirstName}, [Company]”. Obviously, a hard no on spammy subjects (“Increase revenue!!!” or “$$$ offer inside”) as well – those won’t work on and will kill deliverability. You can A/B test a couple of subject line creation prompts to see which get responses noting that you’re not actually tracking open rates here.

Keep in mind, the subject sets the expectation – and it should relate to the email body. Misleading subject lines can also run afoul of legal requirements – as an example CAN-SPAM requires truthful subject lines.

A/B Testing Strategies for Cold Email Campaigns

You won’t get it right on the first try – that’s where A/B testing comes in. By testing different versions of your emails, you can learn what resonates best with your audience and continuously improve performance. Remember that these e-mails are going to be generated by an LLM. So “testing” here is really changing and tweaking the prompt that you give the LLM versus direct editing of the subject lines or body.

Key Metrics to Track and Analyze

Throughout your cold email campaign, it’s essential to track performance metrics. These metrics will tell you how well you’re doing and where you might need to adjust. Here are the key metrics and what they mean:

Tracking these metrics isn’t just about numbers – it’s about actionable insight. For example, a declining open rate over time might indicate that later sends are going to spam, prompting you to pull back on volume or warm-up more. A/B test results feed into metrics to show what’s working. Essentially, let the data guide tweaks to your strategy as the campaign progresses.

Monitoring and Improving Sender Reputation

Your sender reputation is like a credit score for email – it determines whether internet service providers (ISPs) and email services will trust your messages. It’s crucial to monitor this reputation and take steps to improve or maintain it. Here are tools and tactics:

Monitoring reputation might sound technical, but the main idea is: watch the signals (opens, spam reports, Postmaster data) and react quickly to problems. It’s easier to maintain a good reputation than to recover a bad one, so proactive monitoring is your best friend. By keeping your sender reputation high, you ensure future campaigns (and even individual emails) continue to land in inboxes.

Legal Compliance: CAN-SPAM and CASL Considerations

When sending cold outbound emails, you must comply with anti-spam laws, primarily CAN-SPAM (for emails to the U.S.) and CASL (for Canada). Non-compliance can lead to penalties and, more immediately, harm your reputation with recipients. Here’s how to stay on the right side of the law:

CAN-SPAM (USA) – The U.S. law governing commercial emails:

In summary, for CAN-SPAM, the easiest way to comply is:

CASL (Canada’s Anti-Spam Law) – This is more strict:

In summary, cold emailing is legal in the U.S. as long as you follow CAN-SPAM’s rules, whereas Canada’s CASL requires at least an implied consent scenario. Make sure every email you send clearly identifies who you are, provides a way to opt out, and is sent only to people it’s relevant to. Not only does this avoid legal trouble, but it also builds trust and protects your sender reputation.

By following this comprehensive guide, you’ll set up a robust cold outbound email campaign infrastructure, protect and build your sender reputation, craft compelling and compliant messaging, and continually optimize through testing and AI assistance.

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