Vivaldi․net email: the words "spam" and "unchecked" in mail subjects
I use Vivaldi․net email mostly via IMAP and sometimes via web; it works fine, thank you very much.
But the server adds the mark "***SPAM***" (without quotes) at the beginning of the subjects of some non-spam messages from different senders. Also, the server adds the mark "***UNCHECKED***" (without quotes, too) at the beginning of the subjects of the all PGP-encrypted messages from Facebook. I added the all From:-addresses of those incoming messages to the address book at webmail here, but the server still adds these two marks.
I do not see such server's behaviour as a feature, but as a bug. Is it possible to turn it off?