My fiance emailed some of his friends for their mailing addresses so we could send them a save-the-date. Two different friends emailed him back to congratulate him, but did not send along their address. Does this mean they do not want to be included as guests to our wedding? It's fine if they don't want to attend. I don't want to hound them again for their address. Was it on oversight or their way of saying they prefer not to be invited?