Opera Mail qualifies two nearby identical mails as duplicate
Two very similar mails have been downloaded from server.
The only difference (if to examine its body and the normal header) are the recipient email address and the mail time stamp (receive date).
Bodies are identical.
Both mails are stored in one mailbox/account.
These two mails are listed in mail list view only if to enable "Show duplicates".
Actually these mails should not be classified as duplicates.
Why does Opera Mail do it? Is it maybe a known bug?