verify email opened

once we send email from php using mail() function, is there any way to check either mail is open or not?

may be any type of database insertion code in email..?

or calling any function from website?

any possibility.........

i search on internet all the day but did't found any ans.

Thanks

Small images - called Web Bugs - are the only direct way as Szere Dyeri points out, but they are increasingly frowned upon and blocked by every major mail client for privacy reasons now. I would not consider them a reliable way to tell whether an E-Mail has been read any more.

There is a legitimate way to request a read receipt by adding the following header to the E-Mail:

Disposition-Notification-To: your@address.com

Sending of this notification can be turned off by the recipient of course.

Add an invisible small sized image to the email content. And, let the image point to a unique url on your website. You will know that email is opened once that url is accessed. But this will not work in email clients that does not show images in the emails by default.

I found this web service called Get Notify. They claim they do this for free but you need to verify for yourself.

The only way to do this would be to include an image in the email that resided on your server which includes a key to match to the user you are sending the email to. For example, I send an email to Joe@mail.com. In my database (or other storage system) I have Joe@mail.com matched to key 0100. In his email I include an image, like

<img src="http://www.myserver.com/image/?key=0100" />  

On your server, /image/ needs to return an image, even a 1 pixel .png. Now you have the key that the user was assigned and can act accordingly.

Many people responded that adding a "tracking image" is a "frowned upon" method and 'considered "questionable" activity'.

Out of curiosity lets say we didn't include a separate tracking image but rather we included this method in an existing image like for instance added it onto your companies logo image like:

http://mycompany.com/images/logo.png?track=2742'>

At least with this method your tracking image won't get blocked by any scanning applications.

One legitimate way to do this is to only send textual information in the email asking the user to follow a link which you can then track. Something along the lines of:

//lots of good info to identify yourself/company
Thank you for your request...

Please follow this link: http://somewhere/ for tracking information

Unfortunately this leaves it in the users hands to acknowledge your request. This is considered to be the most respectful way to do it.

If your application is not public facing (i.e. an internal app for your company), then the img src method already posted is a good technique.