4 Ways to Improve Outgoing Email Deliverability to Gmail/Hotmail/Yahoo

NetShop ISP
4 min readMay 18, 2023

One of the most common issues businesses are facing in 2023 is their e-mails ending up in recipient’s spam/junk folder. This problem is often encountered when you are sending email to gmail.com, hotmail.com, live.com and outlook.com. Google and Microsoft (owners of the abovementioned email domains) have strengthen the sensitivity of their spam filters causing legitimate e-mails to be marked as SPAM.

We have prepared a comprehensive guide on how to improve your email deliverability rates and make sure that your emails reach their intended destination.

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Step 1: Check Your IP Reputation

One of the first things you should do is check your IP reputation. This is because many email providers use a variety of methods to determine whether an incoming email is spam or not. If your IP address has been flagged as sending spam in the past, your emails will be more likely to end up in the recipient’s spam folder. Therefore, it is important to regularly check your IP reputation to see if you need to take action to improve it.

To check your IP reputation, you can use a tool such as MXToolbox. Simply enter your IP address into the tool and it will provide you with a detailed report on your reputation.

Step 2: Set Up an SPF Record

Another important step in improving your outgoing email deliverability is to set up an SPF record. This stands for Sender Policy Framework and is a method of verifying that the email is originating from an authorized server. By setting up an SPF record, you are essentially telling receiving email servers that your domain is authorized to send email on your behalf.

To set up an SPF record, you will need to access your DNS settings and add a TXT record. The exact steps will vary depending on your DNS provider, but most will have instructions on how to add a TXT record. You will need to enter the following information:

v=spf1 include:_spf.yourdomain.com ~all

This tells receiving email servers that the domain “yourdomain.com” is authorized to send email on your behalf.

Step 3: Implement DKIM Signing

Another important method of verifying your emails is through DKIM signing. This stands for DomainKeys Identified Mail and is a way of adding a digital signature to your emails to prove that they originated from your domain. This can help to prevent your emails from being marked as spam.

To implement DKIM signing, you will need to generate a public and private key pair. You can do this within the Zimbra Admin Console by navigating to Configure > Global Settings > SMTP Authentication.

From there, click on the DKIM tab and follow the instructions to generate your keys.

Once you have generated your keys, you will need to add DNS records for your public key. Again, the exact steps will vary depending on your DNS provider, but you will need to add a TXT record with the following information:

v=DKIM1; k=rsa; p=

This tells receiving email servers to look for a DKIM signature in your emails and to verify that it matches the public key in your DNS records.

Step 4: Improve Content and Engagement Rate

If you find that your deliverability rates are still not where you would like them to be, there are a few additional steps you can take. For example, you can work on improving your email content to make sure that it is not being flagged as spam by email filters.

To improve your email content and engagement rates, consider using personalized messages and targeting specific segments of your audience. Additionally, avoid using spammy words or phrases such as “free,” “earn money fast,” or “act now.”

When it comes to links and attachments, be mindful of how many you include in your emails. Too many links or attachments can trigger spam filters and negatively impact your deliverability rates.

Finally, be sure to format your emails properly, including clear and concise subject lines, well-written and grammatically correct content, and an easy-to-read layout.


In conclusion, by following these steps, you can significantly improve your outgoing email deliverability when using Zimbra-based emails. Remember to regularly monitor your deliverability rates and take action if necessary to continue improving your email deliverability.

Finally, it is important to monitor your deliverability rates to see if they have improved. You can use a tool such as Mail Tester to test your deliverability rates and identify any potential issues.

Source: https://netshop-isp.com.cy/blog/4-ways-to-improve-outgoing-email-deliverability-to-gmail-hotmail-yahoo/