How to know the sent mail open or not

Unfortunately, there is no foolproof way to know for certain whether a sent email has been opened or not. Email clients and servers don't provide direct access to this information, and most email providers don't store this data. However, there are some indirect methods and workarounds that can help you estimate the open rate of your emails:

1. Trackable links: You can use trackable links in your email campaigns. These links are unique to each recipient and can be used to track clicks and opens. You can use URL shorteners like Bitly or Google's URL Builder to create trackable links.
2. Image tracking: Some email clients, like Gmail, load images in emails by default. You can use this to your advantage by embedding a 1x1 pixel image in your email with a unique URL. When the recipient opens the email, the image will be loaded, and you can track the open. However, this method is not foolproof, as some email clients may not load images by default.
3. Pixel tracking: Similar to image tracking, you can use a small, transparent image (a "pixel") in your email. When the recipient opens the email, the pixel will be loaded, and you can track the open. This method is more reliable than image tracking, but still not 100% accurate.
4. Email client-specific tracking: Some email clients, like Outlook, provide APIs that allow you to track email opens. However, these APIs are typically only available for enterprise customers or require specific setup.
5. Third-party services: There are various third-party services that offer email tracking and analytics, such as Mailchimp, Constant Contact, or HubSpot. These services can provide insights into email opens, clicks, and other engagement metrics.
6. Surveys and feedback: You can include a survey or feedback form in your email to ask recipients about their engagement with the email. This method is not automated but can provide valuable feedback.

Keep in mind that even with these methods, there are limitations and potential issues:

• Some email clients may block or strip tracking pixels or links.
• Recipients may use email clients that don't support tracking or may have tracking disabled.
• Some recipients may not open the email, but still click on a link or respond to the email.

To improve the accuracy of your email tracking, make sure to:

• Use a reputable email service provider or marketing automation platform.
• Use trackable links and pixels consistently across your email campaigns.
• Monitor your email analytics and adjust your campaigns accordingly.
• Consider using multiple tracking methods to increase accuracy.

Remember that email tracking is not an exact science, and there will always be some uncertainty. Focus on improving your email content, subject lines, and segmentation to increase engagement and conversion rates.