When you import an address file, promio.mail checks different things. If the address file is uploaded, you can klick at Details (green arrow) in the target group management and look at the history.

In the example you can see that 5485 addresses should be imported.

• 5387 addresses are left after the syntax check. So in some addresses for example the @ was missing.
• 5042 addresses are left after the blacklist check. 345 addresses are therefore in the negative list and will not be imported.
• Only 3 new addresses were found.
• There were no duplicates.