Email deliverability in 2026 : mission impossible?
In 2026, it is not possible to send even 50 emails per day per mail address... Here is the volume that can generate good opportunities.
4/10/20264 min read
How to Keep Your B2B Cold Emails Out of Spam in 2026
I wasn't working as a Business Developer back in 2015, but I sometimes hear people describe that period as a kind of golden age for B2B email prospecting.
Apparently, all you had to do was send huge numbers of emails to large audiences to get replies and generate meetings.
Today, things have become much more complicated.
First of all, prospects no longer respond to generic, non-personalized emails. On top of that, email providers such as Google, Microsoft and Zoho are increasingly cracking down on B2B cold emails.
Year after year, it's becoming harder to avoid being flagged as spam by their automated systems.
You won't necessarily receive a notification when your emails start landing in spam. However, if your open rate suddenly drops dramatically over a short period, it's a strong indication that your emails are no longer reaching the inbox.
And if you're not even monitoring your open rates, I'm afraid there's not much I can do for you.
These protections are designed to prevent B2B prospects from being harassed, which is understandable.
And that's actually a good thing: incompetent prospectors will end up in spam, leaving more room for people who know how to do proper outbound.
See here for more information on how to prospect without harassing your B2B prospects.
I'm going to share some extremely valuable insights on how to structure your email infrastructure to avoid being flagged as spam almost immediately.
Everything revolves around pre-warming, the number of emails sent per day and per address, the number of addresses per domain, and the quality of your messages.
The Perfect B2B Cold Email Setup in 2026
Email Infrastructure
If you want to run B2B cold email campaigns at scale, particularly as part of a multichannel prospecting strategy, you'll need dedicated domains and email addresses.
Indeed, using your regular professional email address for this purpose could destroy your main domain's reputation and cause your emails to land in spam, including when you're communicating with existing customers.
To summarize the ideal email infrastructure, here's what you'll need:
Zapmail: To purchase affordable domains and email addresses, sometimes even pre-warmed ones (although these are more expensive).
Instantly: To warm up your email addresses, send your sequences and track email opens.
This is probably one of the cheapest and most efficient ways to get started.
After all, most people don't want to deal with setting up an entirely new domain from scratch and configuring 2 or 3 email addresses for it. It's much easier to buy everything directly through Zapmail at a relatively low cost.
The warming process takes several weeks. During this period, the tool simulates realistic email activity to gradually build your email reputation.
Do not use these addresses to send automated prospecting emails while they're still being warmed up.
Warming and Sending Strategy
Previously, it was possible to send 50 to 75 automated emails per day per email address, with up to 5 email addresses per dedicated domain.
Today, email providers' anti-spam systems are much more aggressive. This strategy will get your emails flagged as spam very quickly.
Cold email is considerably cheaper than B2B cold calling in terms of infrastructure, but there are still costs to consider.
Since sending volumes are now more limited, the fixed costs of email prospecting infrastructure have also evolved, although it remains relatively inexpensive.
In 2026, here's the setup I'd recommend to minimize the risk of landing in spam:
Warm up your email addresses for 4 to 6 weeks, gradually increasing the volume to 20 emails per day.
Then maintain 10–15 warm-up emails per day per address while starting to send 10 actual prospecting emails per day per address.
In terms of infrastructure:
Use a maximum of 2 to 3 email addresses per subdomain. You can use 3 if you're sending 10 emails per day per address, or 2 if you're sending 25.
So, if you want to send 120 automated emails per day, here's the kind of infrastructure you'll need in 2026:
4 different domains dedicated to automated cold emailing.
3 email addresses per domain, each sending 10 emails per day.
With Zapmail, this would cost approximately:
€90 in setup costs: Domains and email addresses.
€45 per month: Monthly email address costs.
€45 per month: Instantly subscription for sending and warming.
€55 per month: Apollo.io subscription for finding email addresses.
Cold calling is more expensive (often at least €150 just to obtain the contact details of 500 people), but it's considerably more impactful than email prospecting. It can therefore generate more meetings from a relatively limited number of prospects.
However, this only works when you have a good cold-calling technique that actually delivers results.
Getting Results With Cold Email: Using AI and/or Advanced Scraping Strategies
Having the right email infrastructure will help you avoid spam, but it doesn't guarantee that you'll actually book meetings!
In 2026, prospects stopped paying attention to generic automated emails a long time ago.
Your messages need to be particularly relevant and/or personalized if you want people to read them.
I've personally developed a specific B2B email sequence generation strategy based on AI and n8n, which allows me to generate personalized emails for each individual prospect.
It's not a workflow that can simply be replicated across every market. I developed it specifically for my own market, although the approach could potentially be adapted to other industries.
Even though the process is automated, the recipient gets the impression that the email was written and sent by a real person specifically for them.
This significantly improves both open rates and reply rates.
See here for more information on how to use AI in B2B prospecting, beyond the usual clichés and misconceptions.
Conclusion: Zapmail, Instantly, Apollo and 10 Emails Per Address
There's no denying that there are quite a few tools to master, but the process isn't that complicated.
Identifying the right prospects, scoring your market and finding their email addresses can actually be fairly complex, especially when using Apollo.
Building a good prospecting list isn't particularly easy, yet it's the first and most important step in any successful prospecting campaign.
Once you've got that sorted, using the tools and methods I've mentioned in this article should help you achieve good results.
And if you don't feel like dealing with all this yourself and would rather focus on closing deals, feel free to contact me on louis@outbound-machine.com
This also applies if you're looking for coaching or support to improve your prospecting skills, or if you're considering outsourcing your B2B sales prospecting.