Send emails that land in the Inbox [Updated 2023 Guide].

Written by SalesMix
Last modified Jun. 11 2023

I keep hearing that email is a lost cause due to the dreaded spam box. Conversely, email has helped founders grow and scale their businesses and continues to be used today by many startups and small and even large businesses as a strong outbound channel for growth. So the barrier seems to be the process in which email is being used.

If you send spam, you will be considered spam. How can you send a high volume of emails that reach inboxes and are not considered spam by your email service provider? The trick is in segmentation; just as we segment audiences for specific offers, similarly, we need to segment the traffic we send to email service providers.

In this guide, im going to walk through the thought process of sending bulk emails that reach the inbox.

How to calculate your ideal email sending volume

Your ideal sending volume is NOT your total volume of sends you hope to do per email. It's actually the total overall volume of emails you want to send over a set duration.

Let me explain.

If you wish to send 50,000 emails, ask yourself over what duration of time I am looking to send all 50,000 emails. Is it over a week, a month, or 3 months?  In our example, im going to use 50,000 emails over a month for the sake of simplicity.

If my niche is one in which my customers only read their emails on business days, This could be B2B saas, service sales, or other types of software sales. Some Industries, such as real estate, are better to reach out to on the weekend because these buyers or sellers might be more available on the weekends.

In any given month, if you are only sending on business days, there are about 22 business days. So you take your overall sending volume, which in this case is 50,000 emails, and you divide it by your available sending days, which are 22. If we do this calculation and round it up, we get 2,273 emails sent daily.

Obviously, if you try to send 2,000 plus emails a day, you will land in spam. I often hear people saying that Google G Suite allows us to send 2,000 emails daily, and it's in their documentation.  While that may be correct, and such documentation does indeed exist, the sender fails to realize that this specified sending volume is within the individual business, not for external and cold Outreach.

In our case, what we have to do is not only restrict our sending volume from the overall 2,000 per day but also have to prime our email and domain to warm it up so that it can reach our desired sending volume while also landing in the inbox.


How to prime and warm up an email

When you initially purchase your domain, especially if it's a brand new one, you will come out with a neutral domain authority, especially with your email service provider. Once you add your Google G Suite to your domain and are ready to send emails, sending out an increased volume of emails is the fastest way to land into spam. It's an immediate red flag.

At the end of the day, it's all about reputation, and email reputation is just like any other reputation. Your new domain is a newcomer in the eyes of your ESP; they want to see good behavior, which means sending emails that people want to read but sending them at realistic volumes.

So our goal in the initial days of our new email’s life is actually to send 2, then 4, then, 6 then 8 and preferably randomized volumes of emails every day to inboxes that will not only open them but spend time reading them and hopefully even reply back to them. This allows us to increase our domain and email reputation.

I'm sure you're thinking; this is a hassle in its own right, and there has to be a better and easier way to do this automatically. I'm glad you asked because that's actually true; introducing email warm-up.

So what is email warm-up?

Email warm-up is a process of sending staggered emails each day to increase your overall sending volume from an email address while increasing your domain reputation. At SalesMix, the way this process works is actually very easy.  Once you connect your email to our system and you enable warm-up as an option, your email becomes a node within our network; each sending email address added to the system is its own node. 

Each day emails are sent from one node to another, these emails are automatically opened and read, and a percentage of them are actually replied to. I'm sure you're wondering who writes these emails, how they are opened, and how we choose which ones to reply to.

With the onset of AI technology, we can generate new emails including your company information, your custom offers, and your custom signatures and use them within the warm-up process. So now, when a warm-up email is sent to another node, it's actually using your company information, so if that email lands in spam, we can remove it from spam and move it to the inbox because the whole network is controlled. Remember that this removal from spam and move to inbox only happens for the warm-up process, not for campaigns.

A majority of times, when we send out emails with our company name, sales offers, and signatures, they tend to land in spam. But because our warm-up process incorporates all these custom features, we can prime ESPs to expect these items in the email.  Each time we open the email, read it, reply back to it, and, if needed, remove it from the promotions, other and spam folders. We are basically giving your email and domain a positive indicator for its email reputation.

So how long do I need to keep the email warm-up active?

Ideally, the answer is always, but it should be a portion of your overall sending volume for the day. What I mean by this is that if you're sending 50 emails per day after your initial warm-up period, maybe 5 to 10% of these emails should be warm-up emails, and the remaining should be your outbound campaign emails. There is actually a very good reason for this. Let's hypothetically say you are sending 50 cold emails per day.

Because 5 to 10 of those emails are within the warm-up Network and they are controlled, you know for a fact that they will be read, and even if they land in the spam or promotions folder, the system will automatically give positive indicators for them so at least 10 to 20% of your outbound traffic will always have a positive signal now from the other 40 to 45 emails that are cold you have a higher likelihood of reaching the inbox and ensuring that your reputation doesn't get damaged.

The fastest way to damage your email reputation is constantly sending emails that land and spam or are marked as spam. So let's hypothetically say out of the 50 emails, 5 are consciously marked as spam by the receivers because you had warm-up active even during your cold campaign. You can almost negate these 5 email receivers because you had five positive signals with possible positive replies.

So you might be wondering if I can send 50 emails from day one, and the answer is actually no, that's not a great idea; you want to prime your emails over time to that volume of 50 per day.  We do this by staggered sending in the warm-up process.

How long do I warm up before sending cold emails?

We reach the ideal 50 emails per day volume after a 2-week period, and we start sending our first cold emails after 3 weeks.

A randomized staggered cold email-sending schedule would look something like this: 

Day 1 - 2 emails sent
Day 2 - 5 emails sent
Day 3 - 7 emails sent
Day 4 - 10 emails sent
Day 5 - 13 emails sent
Day 6 - 14 emails sent
Day 7 - 18 emails sent

Day 8 - 24 emails sent
Day 9 - 30 emails sent
Day 10 - 32 emails sent

Day 11 - 35 emails sent
Day 12 - 38 emails sent

Day 13 - 40 emails sent

Day 14 - 45 emails sent

Day 15 - 50 emails sent
Day 16 - 50 emails sent
Day 17 - 50 emails sent
Day 18 - 50 emails sent
Day 19 - 50 emails sent
Day 20 - 50 emails sent
Day 21- 50 emails sent
Day 22 - 5 emails sent in warm-up + 45 sent in a cold email campaign


What's amazing about this process is that our system allows you to control your warm-up, sending volumes to be randomized, sequential, or exponential based on your choice and comfort.

What's the ideal number of cold emails to send from one email?

The question needs to be taken a step further back. Usually, people purchase multiple Google Gsuites/workspace accounts for a single domain. For example, they will purchase and then purchase gary@salesmix, jessica@salesmix, and James@salesmix; while these are great for normal team emails and business emails, these are never a good idea for cold emails.

There are a few reasons why:

1. Domain reputation vs. email reputation

2. Business Domain vs. cold email sending domain

3. Sending from singular domain vs. multiple domains.

Let's start with the first one. There is a difference between your singular email reputation, [email protected], and your actual domain itself, If [email protected] starts spamming, it will definitely affect the singular email, but it will also start affecting the main domain.

For example, let's say at SalesMix; we have 20 users with business emails using the main domain; out of these 20, only James is spamming, and his overall spam volume is not too high, maybe only 20 emails a day. Eventually, these emails will start being marked as spam and will start hurting everyone else in the company as the reputation flows up to the domain level. So Susan in HR will start noticing her emails are mysteriously landing in spam!

One surefire way to help is to ensure all company emails are added to an email warm-up system at a low daily volume for long-term reputation security purposes. But the real question is, was it a good idea for James to use the main company email as a cold email-sending domain?

What domain or email should I send cold emails from?

The short answer is not your main business domain.

The reason for this might be obvious to some but not to many. When your main day-to-day business email is used for cold email sending, you tremendously increase the risk of this domain being marked as spam. In the case of James above, if he continues to send cold emails and those emails get marked as spam, over time ESPs will mark the domain reputation of the main business domain as low/suspicious making it almost impossible to conduct day-to-day business operations via email.

So what domain do I send emails from, actually? You create your first sales domain. A new domain used solely for the purpose of outbound cold email outreach. For SalesMix, our marketing teams have used domains such as or The emails we create from these domains are the names of our account managers or sales reps.

So if one email can send 50/day safely, can I buy one domain and create 10 emails from it, sending 500 emails daily from a singular domain?


Cold email sending from one domain vs. multiple domains

Do you remember what happens when you have multiple emails under a single domain, and one of the emails starts getting marked as spam? It infects the main domain’s reputation and thus harms the individual reputations of each email address associated with that domain.

So what's the solution?

In our example above, we needed to send 50,000 emails over 22 business days, yielding around 2,273 per day. Now if we divide that by our actual sending volume, which is 45 emails a day for cold emails (remember 5 emails a day for warm-up), this gives us 2273/45 = 50.5 emails needed. Once we round up, that's 51 emails needed to have a safe cold mail sending volume of 2273 emails daily!

We head over to Google domains and purchase 51 domains.

We aim to have a 1:1 ratio of domains to emails, one sending domain to one email. So with each Google domain, we buy, we make sure to purchase a Google Workspace account as well. ? If you want to ensure that you're using the lowest level starter pricing, if Google doesn't allow you to change pricing, go through the whole process and then go back into billing and change your plan level. This ensures we pay the least amount possible for a Google Workspace account.

How do I Connect my email to SalesMix for Warmup and Outreach?

Now that you've purchased your domains and workspace accounts, you're ready to start warming up your emails, and the next step is to connect these emails to your SalesMix account.

Login to SalesMix, head to the email accounts section on your right, and click Add email. You will see a popup that looks like this:



Select your email provider; in this case, that would be Google. Follow the on-screen instructions to enable IMAP. IMAP is a setting on your Google account that allows access to incoming emails. Once this important setting is enabled, select next, and you will find two options.


Because we are using a Professional domain and google workspace and want to have more stability, we will use option 2.

This requires us to go back into our google workspace admin area again. Be sure to follow these steps:

Allow SalesMix to access your Google Workspace

  • 1. Go to your Google Workspace Admin Panel
    On the left-hand panel, click show more and find the security tab.
  • 2. Click on “Security > Access and data control > Api controls” from the menu.
  • 4 . Then click to “Add app > OAuth app Name Or Client ID”.
  • 5. Use the following client ID to search for SalesMix:

Input this client

6.  Select and approve “Trusted Can Access all Google services” for SalesMix to access your Google Workspace.

Now your account is set up and ready for warm-up and cold email campaigns!


How do I enable Warmup for my emails?


Setting up warm-up once your emails are connected is just a click away.

Just click on the warm-up toggle, and you will see a few settings you can control.  


The first set of settings controls your email interaction within the network and system. You can set your maximum warm-up email sending an amount to ensure you do not exceed your service provider limits.

The max interaction field allows you to control total interactions, which include sending, receiving, replies, etc.

The ramp-up value is the initial value from which your email will start and gradually increase. For example, a ramp-up value of 2 will mean the first day, your email will send 1-2 emails and then gradually increase warm-up sending from there onwards.

The current interaction limit allows you to control the number of interactions that happen per day to your email.

The reply rate should never be more than 30% to be natural. However, you can set this higher if needed. The default values allow you to start warming up your email safely and securely.

Do warm-up emails automatically disable?

Warm-up emails will continue to send until you actually manually disable them. Once you start your campaign, keep your warm-up sending volume in check to ensure you do not exceed your email service provider limits.

My Wamrup emails are automatically disabled. What should I do?

It's possible that the system automatically disconnects you; this means that your email has some issues with deliverability. Some of these could include SFP records not being set up, DKIM issues, or other deliverability issues related to the reputation of your email or domain. We discuss how to fix such issues in our email deliverability guide.

The system will automatically disable your email in order to protect other emails within our system. When one email within the system is causing bounces, it can affect the remainder of the email pool. Our system detects issues with your emails and auto-removes you from the pool if any email deliverability issue is found.

It is possible however, that your email SMTP/IMAP connection was served or your credentials changed. This could cause a disconnect with our systems.

How are warm-up emails created?

Users often wonder if they have to write warm-up emails manually, manually interact with them, remove them from spam, and then manually reply. And the answer, of course, is no! 

The system will use AI to draft email copies, complete interactions, and even write reply emails. Most importantly, the system scans your promotion boxes, other boxes, and spam to see if any warm-up emails have landed there. If they have, the system will move them automatically to your inbox.

To create warm-up emails, you must ensure your email is connected, and the correct settings are used, as mentioned above.

Can I customize Warm up emails with my offer?

With SalesMix, you can! We understand how important it is for you to be able to warm up not just your email and domain but offer text and keywords as well so they don't get picked up by spam filters during actual campaigns.

We have created a unique system that lets you add your company information, signature, location, and offer details, including service name and price, to your warm-up email. So when the AI generates email copy, it uses this information to draft emails for sending as well as replying.

Usually, spam filters will pick up company, pricing, offer details, and mark emails as spam, so this practice allows you to prime ESP with positive interactions through the SalesMix warm-up process.

To set this up, fill out the warm-up fields below.


Why are my emails landing in spam? I enabled warm-up!

Just because you enabled warm-up and followed everything to the dot above in this guide doesn't mean your emails will always reach the inbox. There are many factors to email deliverability; the above were just some basics to help you get started.

A few things affect our email delivery to the inbox:

  1. Your domain and email reputation
  2. Your email copy
  3. Links within your email
  4. How many people mark your email as spam
  5. Set up of DKIM and SPF records
  6. Tracking links

Our guide covered everything with theory, basic setup, and domain and email reputation.

Once you have started your warm-up process and you have started sending emails out, you will notice an improvement in your email delivery. We review the above-mentioned points in our Enhance Email Deliverability Guide to further enhance email deliverability.