migration-pst - Ten Thousands of Warnings

[boospy]

Hello all,

we migrated an MS Exchange to Kopano. On one Account 20GB of Mails, we got during the Importprocess this warings:

2020-08-03 12:51:02,072 - migration-pst - WARNING - no email address found for receiver property, skipping
2020-08-03 12:51:02,111 - migration-pst - WARNING - no email address found for receiver property, skipping
2020-08-03 12:51:02,111 - migration-pst - WARNING - no email address found for receiver property, skipping

What does it mean, really, i found nothing over. It is only a waring, so it this important or not?
Copano Core 8.7.14

Very Thanks