Distinct Count based on another column values

[Maryam_Pour]

Hi All,

Hope you can help me with the DAX.
I have a big table of all Mails for different projects. Sometimes, the same mail number is duplicated both in Inbox and sent box, as some people add themselves as receivers when sending mails.
We use a system that generates the same mail number based on the type of mail, no matter which projects.
Therefore I have several duplicated mail numbers from different projects, which I only need to count one time.

How can I get the total count/distinct count of all mail numbers accros projects?

[amitchandak · Accepted solution]

@Maryam_Pour , if only one mail no per project

countrows(summarize(Table, Table[project], Table[mail no]))