Sometimes there are mails receifed that include only one file encap2.ond. As seen earlier ond meand one note database.And therefore this database can be saved on disk and opened via file->open->database from within the memo.
This only happens with mails to other notes clients via internet (option set in advanced options)
But why is that?
we figured out, the problem is an entry whithout email address in personal address book of the sender for the same name.
Perhaps this entry is just for telephone number and email address is in central address book.
So just change the name and restart Notes client.