the following two methods should not be mentioned, because they have been tried, and each has its own disadvantages, so it has been decided to give up and will not be considered

1. Embed img images, and src write a URL < src= "xxxx?email=12345@xx.com" alt= "width=" 1 "height=" 1 "
border=" 0 "style=" height:1px! important;width:1px "/ >

2. If you ask for a receipt, needless to say, you can"t give up o (reply receipt) o

is there any other way besides these two methods? What methods are popular in foreign countries at present?

demand: 1. Be able to count specific people, such as e-mails opened by people who know email=12345@xx.com

2. Try to avoid being blacklisted or rejected because something is embedded in the statistics (the img method was abandoned because it was added to the blacklist)

Thank you