How to Avoid Email Spam Filters and Reach The Inbox?

Aleksandra Duło, 6 February 2023


How to avoid having my messages stopped by the spam filter?

Your customers’ inbox certainly has protection set up to prevent unwanted emails. However, to pass their validation, you only need to follow the rules described below. This will ensure that you reach recipients with your emails so that they be able to view the offer and consciously decide to use it.

See how to stay out of spam.

How to avoid email spam filters and reach your audience? Check out these proven methods

Spam in the mail represents up to 50% of the messages sent every day. For this reason, the use of spam filters has become a necessity. Recipients are unable to read such a large number of emails, especially those reaching corporate mailboxes.

Spam filtering programmes use various algorithms to determine whether a message is wanted by the user or not. They may focus on: headers and content, examine identifiers assigned by users, not pass addresses from blocked lists or only allow the receipt of emails from the Safe Senders list.

Therefore, an email deliverability strategy is needed to bypass spam filters and reach recipients’ inboxes.

Maximize your email deliverability and security with EmailLabs!

20 ways to avoid landing your emails in the spam folder

Send emails from your domain

Firstly, always send emails from your own domain, i.e. one whose address is the same as your website. Sending newsletters or other bulk emails from different domains or free email addresses like Gmail increases the likelihood of ending up in spam.

Algorithms unable to determine the sender’s identity will assume that they are sending spam. It is also important to use a single sender name with a simple and credible name, such as first and last name@, newsletter@ or marketing@.

Authenticate your domain

The second important aspect is to authenticate your bulk email domain so that the email service provider can send them on your behalf. This will ensure that the filters treat you as a reliable message deliverer.

Authenticate with DKIM

DKIM is used to validate emails – it verifies that an email was actually received from a given email address .A digital signature is emitted from all emails sent. These are encrypted data including message body or header, email address, and other data. If an incoming server receives a DKIM message, it recreates the signature in the corresponding public key. A matching email can significantly enhance deliverability. In a failure scenario this will be interpreted by the server as hinting at the possibility that the receiver is not what the sender claims.

DKIM authentication


Setting up DKIM helps prevent your emails from landing in the SPAM folder.

It is also important to build and maintain a good sender reputation. It is given based on the quality of the campaigns sent out, their frequency, the number of recipients and their engagement. It can be negatively affected by the following factors:

  • reporting and marking emails as spam by users (spam complaint rate),
  • rejection of emails sent to recipient addresses that no longer exist (high number of hard bounces),
  • hitting a Spam Trap i.e. addresses used specifically to catch spammers

Monitor the reputation of your sender’s IP address

Your email delivery depends largely on your sender’s reputation – if your sender’s IP reputation address is bad, messages can’t get into the recipient’s inbox. DNS stuff can tell you if you’ve been blacklisted from emails — something most unlucky e-mailers do not know!

Decide between Shared and Dedicated IP addresses for sending

Another key point is to check the reputation of your IP, a string of numbers that defines the identity and location of the server. It also determines to what extent your network is trustworthy when it comes to communication and information.


You can use a shared or individual IP address. Either solution has its good points.

With a dedicated address, you build up your own reputation and this will not be damaged by the actions of other users. With a shared address, on the other hand, you do not need to send a large number of messages per month to maintain a certain status, as a trusted email sender.

When choosing an email service provider (ESP – Email Service Provider), it is, therefore, worth checking what features it offers and how it takes care of the reputation of the servers.

Comply with anti-spam laws

It is also important to optimize the emails you send in terms of their assessment by the spam filters. To be considered valuable, messages should be:

  • short – there is no one specific length, it is best to fit in a maximum of 200 words,
  • written without excessive exclamation marks,
  • without capital letters that give the impression that you are shouting at the recipient,
  • typed linguistically and stylistically correctly,
  • without text written in red, better to stick to the proven black font.

Offer recipients both an HTML and a plain text version of your emails

HTML emails use HTML format which allows you to create attractive email messages using attractive graphic elements. By offering both the plaintext and HTML versions of the same email you not only signal that you are legitimate to your service providers.

Avoid trigger words or misleading subject lines

The next method is to avoid certain words that suggest in advance that you are sending spam. Such risky phrases include those that indicate desperation, e.g. don’t miss out or click here, an intrusive nature, e.g. act immediately, or are unlikely, e.g. win 1,000,000 or 100% free.

Optimize your image-to-text ratio

Be careful about the size and number of graphics in your emails. Spammers have already tried to bypass spam filters by sending out emails containing only an image.

As a result, nowadays, a newsletter that has less text than pictures is more likely to end up in the spam. In addition, some email clients, such as Gmail and Outlook, do not display images by default unless recipients set this option or add the sender to the Safe Senders List.

For good deliverability, ensure that images do not exceed 40% of the email volume.

Maximize your email deliverability and security with EmailLabs!

Test your emails before sending

A great way to check if your email will bypass the spam filter is to test it before sending it to customers. For this purpose, it is best to use the Seed List created in the most popular mailbox providers to verify the correct display of the email and inbox placement.

Such a test email will allow you to check the layout and readability of the text and improve it if necessary. In doing so, it will show whether it will be classified in the inbox or as spam.

Don’t buy or rent email lists

If you want your messages to reach their recipients, do not use pre-purchased mailing lists. These usually contain a lot of outdated or non-existent addresses and spam traps, by which you may be considered a spammer. In turn, the newsletters you send will be marked as junk mail. Always use lists of your own customers who have agreed to receive information from you.

Honour your unsubscribes and remove them from your mailing list

Allow users to unsubscribe. No such option may result in your messages being straight-marked as spam. Recipients want a choice, and by giving it, you increase your credibility.

In addition, you can use the unsubscribe as an opportunity for the customer to complete a short survey about why they are cancelling their subscription. Analyzing its results will help you eliminate mistakes in the future.

Provide double opt-in

Make double-opting forms possible. The user submitting the subscription will receive confirmation by e-mail. If you confirm your subscription, you will reduce your email spam rate. Double opt-in will decrease the chance of the subscriber reporting that you’ve posted something that’s deemed spam.

Use thoughtful headlines

Leverage the right email headline (and preheader). This is the element that recipients see first, determining whether or not they will open it fully. It should be concise and clear, without capital letters, an excess of exclamation marks and the risky phrases described above. You may want to help yourself with one of the many guides on creating message headlines.

Regularly clean and update your recipient list

This is a proven way to optimize email deliverability and keep subscribers engaged. A clean list reduces the risk of hitting spam traps and losing your reputation as a sender.

Follow the guidelines for sending out emails delivered

Show that you are a reliable sender. First of all, include your registered office address in the footer so that recipients know they are dealing with a legitimate company. Also, inform them of the possibility of opting out of receiving emails from you and respect all such requests immediately.

This will increase your credibility and improve the deliverability of your emails.

Whitelist? Yeas, please.

Ask your subscribers to whitelist your address. The white list contains the addresses of trusted senders for that user. Being included ensures that messages sent from you should not be treated as junk mail.

Check your link quality

Check the quality of the links you include in the messages you send out. They must direct to worthy domains. Your good reputation as a sender is linked to their reputation, so recipients must not be redirected to suspicious external sites.

Use tools that are designed to check the quality of mailings

Such as This system tests whether a message will be considered valuable and make it to inboxes, treated as suspicious and end up in the spam or rejected by the receiving server right away.


Reach your audience effectively with EmailLabs!

You already know how to avoid being stopped by spam filters to reach as many recipients as possible. If you care about the high effectiveness of your transactional emails as well as marketing, we invite you to work with us.

We deliver a server infrastructure and access to an analytics panel, which, thanks to integration using email RESTful APIsand SMTP interfaces, guarantee deliverability of emails of up to 98.8%. We ensure email safety by using appropriate authentication protocols and security. If you need additional information about our offer, please feel free to contact us!

Read more about our service in the Cybersecurity and Cloud SMTP Integrations tabs.

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