Don't request the HeaderId.Unknown header from IMAP if it is included in the list
Don't request the HeaderId.Unknown header from IMAP if it is included in the list

mganss/MailKit,nachocove/MailKit,matt2003/MailKit,sstraus/MailKit,jamie-dainton/MailKit,jstedfast/MailKit,dsbenghe/MailKit,FubarDevelopment/MailKit,eino-makitalo/MailKit