Technical Advice on Ensuring Good Deliverability
Chris Traczyk avatar
Written by Chris Traczyk
Updated this week

To make sure your emails are delivered to prospects, below we share our technical tips that will boost deliverability and minimize the risk of being marked as SPAM.

Here are some most important things that you should take care of in terms of deliverability:

DNS setup

In order to optimize your domain settings, take a look at our DNS Setup guide, where we explain this topic in detail.

NOTE: Deliverability setup → As of February 1, 2024, new email sender requirements by Google and Yahoo! require email authentication from custom domains. Non-compliant emails risk being marked as spam or not delivered. Repeated offenses may lead to domain blacklisting. Our Done For You service offers two levels to help ensure compliance - a basic one, and an advanced one. Learn more about it here: click!

Email setup

It’s a good idea to use an email account with an established domain reputation, as email filters tend to penalize new accounts. Why? It’s a common practice used by spammers – they create new accounts with no history and send out mass emails. If you use your existing account and follow all of the deliverability guidelines mentioned in this resource, you should be safe!

If your email account is new, remember to add all necessary information to your Google or Outlook profile, including your full name, photo etc. You’ll also need to ‘warm it up’ for 2-4 weeks. The best way to warm up your non-Gmail inbox is by using our own tool called Warmbots. Unfortunately, from 1 June 2023 warm-up functions of Warmbots are turned off for Gmail inboxes - you can read more about it and how to maintain good deliverability in Gmail here: click!

NOTE: Warmbots for SMTP/IMAP email accounts is now working in the same way as for other integrations, so the tool is available to a broader spectrum of email accounts! Read how to connect Gmail account via IMAP/SMTP here.

Also, keep in mind that if you created a separate domain specifically for outbound, it's very important to set up a URL forwarding to your company's website. It's highly recommended, because it makes your domain more credible, which can improve deliverability.

What’s the difference between an email account and an email domain?

All email accounts that are set up on a single domain share its reputation. This means that, in extreme cases, an incident that happens on one user’s email account might affect the entire domain.

However, a single email account also has its own reputation, so whenever a deliverability issue occurs, it will first become apparent for the particular email account – giving you time to react.

We recommend that you use a business address like ‘’ instead of role-based email addresses, such as ‘info@’, ‘sales@’, etc. Emails sent by individuals look more natural and less automated – just as if you sat down and wrote them yourself.

Also, your email account should have a profile photo updated! It is quite important now, as it makes your sender's reputation more credible, which also can have impact on the deliverability.

Deliverability tests

You can conduct a deliverability test to make sure that your account or domain reputation is healthy.

  1. On your email account menu unfold Actions

  2. Choose Perform Deliverability Test.

  3. Ideally, select a template that you’ll use in your outreach. If that’s impossible because the template is still in the works, use a dummy template similar in length to the one you’ll be using later. Bear in mind that sending out a message that says “this is a test message” will give you false-positive results.


What should I pay attention to while conducting a Glockapps test?

At Growbots, we recommend using Glockapps to nail down issues that could impact your deliverability rates.

Make sure to always check the following:

  • Sender Authentication (if DKIM and SPF are passed)

  • Google Spam Filter (neither marked as ‘SPAM’ nor ‘PHISHY’)

  • G Suite + Gmail → All “Primary”

  • Exchange (Office365) → “Inbox”

If your results meet the above criteria, your emails reach prospects’ inboxes!

If you target large companies, make sure you:

  • Receive a “Barracuda will deliver your email to Inbox” message.

  • Check Mimecast Email Security → “Inbox”

The following factors won’t influence your emails’ deliverability:

  • Being on a black list (there is no correlation between ending up in SPAM and being on a black list)

  • GlockApps marking your messages sent out via Outlook as SPAM (GlockApps test will always mark your Outlook messages as SPAM, and it’s no reason for concern)

What to do when Glockapps shows that you are landing in SPAM in over 30% of cases? Try to fix your account/domain authority. Take a look at this article to learn how to get out of SPAM.

For more information on how you can use GlockApps to test your deliverability, check out this article.

Sending limits

In order not to exceed your email provider sending limit and get flagged as SPAM sender, it is safe to send no more than 100 messages/day. You can set this up in your email account settings (here you can find an exact instruction).

Also, you should keep the limits lower for the email accounts that are yet warming up. Here are some possible scenarios and our recommendations for them:

  1. At the beginning of your journey with outbound in Growbots, (for both brand-new email accounts and those that were already used in outreach), we recommend warming them up for at least 2 weeks before starting sending campaigns, and then set up the advanced sending limit in a way that there would be twice as many follow-ups as initial messages: initial messages - 20, follow-ups - 40).

  2. Monitor your deliverability (you can do that in your Warmbots dashboard), and if it looks good, increase the limits after 2 weeks to send: 27 initials and 53 follow-ups.

  3. We recommend keeping the daily sending limits at 100 messages per day or less, so after another 2 weeks you can increase the limits to 35 initial messages and 65 follow-ups. Those limits are especially important if your email's provider is Google.

NOTE1: Since Google has a very strict policy when it comes to mass mailing, we highly recommend not to send more than 100 messages per day if this is your email provider. We put emphasis on that to make sure your domain's reputation doesn't get affected in any way.
NOTE2: If you haven’t heard about Warmbots before, this is our very own warm up tool that sends emails from your email account to other network members. It builds up your domain and account reputation through a variety of actions, for example by replying to your emails and taking them out of the junk folder. You’ll also receive emails from other members and reply to them automatically. You can also check this article to learn more about warming-up your account with Warmbots.

Opens & Clicks tracking

If you want to track these statistics in Growbots, make sure that your CNAME record is set up correctly!

We recommend tracking open rates after sending your first campaign and optimizing your subject line, if the open rate is below 30%. However, bear in mind that to track open rates we embed a very small image in your email which might negatively impact your deliverability in the long-term. When you notice that your open rates are stable, you can consider switching it off and, instead, checking your deliverability by monitoring the response rate and doing a Glockapps test periodically.

In terms of deliverability, click-tracking might also have an adverse effect, as it makes the links longer and less attractive. Therefore, we recommend using it with caution, i.e., with a specific goal in mind. For instance, you might find it useful if you want to know who clicks on your link because you plan on executing an extra sequence step (for example, calling them or personalizing the next email). The bottom line is, you shouldn’t opt for this functionality unless the data isn’t truly important for your business.

You can find more useful information about opens & clicks tracking in this article.


Signature, even though it may seem like a detail, has a very big impact on your deliverability. We highly recommend not putting there any links or images - the more basic it is, the better. However, it's best to have there a physical address of your company and a phone number. It makes your messages look more credible!

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