Step 1: Check your email content

• Contacts won't open your emails if the subject line and pre-header don't spur their interest. In addition, if they are misleading or contain spammy phrases, your open rate will be affected. See how to craft a dynamic subject line.
• CTAs help you measure clickthrough rate. Check if the CTAs are easily visible and accessible. If they are not properly designed and placed, your campaign's performance will drop.
• Ensure that you maintain a standard design for all your emails so that contacts can easily recognize you.
• Verify if the content you offer is relevant to the contact's needs and interest. If you keep providing irrelevant content, contacts will either mark your emails as spam or unsubscribe.
• If your email content is verbose or contains only images, your emails might resemble spam. Your email must contain images along with supportive text, your company's logo and contact details to avoid getting flagged.

Step 2: Check your sender address

• If you send emails using a different sender address every time, your contacts won't recognize your emails. To achieve better email engagement, you must send all your emails from the same sender address. See sender recognition.
• If you are planning to send emails from a new sender address, inform your contacts about it and ask them to add the sender address to their address book. See how to add a sender address to the address book.
• Don't use sender address like no-reply@yourdomain.com or hello@yourdomain.com as spammers mostly use such addresses. It is also advisable to have a reply-to address so contacts can reach you for queries regarding your emails or product/service. See why you should avoid no-reply addresses.

Step 3: Analyze your sender domain's reputation

• Domain authentication is a validation mechanism used to prevent the misuse of your domain and improve its reputation. You must authenticate your sender domain to achieve better email deliverability. Gmail and Yahoo (since February 2024) and Outlook.com (since May 5, 2025) require SPF, DKIM, and DMARC from senders of 5,000 or more emails a day.
• Gmail, Yahoo, and Outlook offer inbox placement based on the sender domain's reputation. If most of your contacts use these mailbox providers and if you send emails from a sender domain that has a negative reputation, inbox placement will be severely affected.
• If most of your contacts use Gmail, you can use Google Postmaster Tools to check how Gmail treats your sender domain. Google has retired the Domain and IP Reputation dashboards, so look at the Spam rate and Compliance status dashboards instead, and keep your spam rate below 0.10% and never reach 0.30%.
• For other mailbox providers, you must check your soft bounce report to understand why your emails have been rejected. The possible reasons for email rejection can be spammy content, user complaints, policy-based rejections, email throttling, or negative reputation of the sender domain.
• If you're using a new sender domain, you must warm it up before sending bulk emails. Learn why you shouldn't send emails without warming up your sender domain.
• If you're sending emails using a secondary sender domain, add a note about the reason for using a secondary sender domain in the email footer.

Step 4: Check the quality of your mailing list

• If your mailing list contains invalid email addresses and disengaged contacts, it will negatively affect your campaign's performance. See mailing list pruning.
• You must constantly weed out disengaged contacts and win back idle contacts. A huge mailing list will not guarantee ROI, but a healthy mailing list will.
• If you keep deleting your mailing lists and replacing them with new ones, your campaign's conversion rate will drop as you won't have built a loyal customer base that is interested in your product/service.
• You must segment your contacts based on their interests/needs and send relevant campaigns to keep them engaged.

Step 5: Streamline your email sending practices

• If you send emails during the wee hours, your contacts may miss out reading them. The timing of these emails might also annoy them. Be sure to consider the time zone of your contacts before sending emails.
• If you send emails on festive days, holidays, and on big sale days like Black Friday and Cyber Monday, the likelihood of contacts reading your emails is remote.
• Send emails to your contacts during the time of the day or week when they are likely to read your emails to achieve a better open rate. See send and schedule email campaigns.
• If you don't maintain a consistent email frequency, your contacts will forget that they subscribed to receive your emails. You can set a ceiling with frequency capping.
• For deal-based campaigns, if the deal starts within the next 24 hours, it is not advisable to send emails based on the recipient's optimal open time or time zone. This is because it may take 24 hours to finish sending and your emails may be delivered after the deal has expired.