Now Telegram has a great opportunity to protect yourself and your life from unwanted contacts, especially from scammers.. This may sound like advertising, although I do not pursue such goals, but buying a premium account allows you to receive messages only from those in your contact lists or those who are permitted to do so. Wouldn't it be worthwhile to invest this modest amount for your peace of mind and to avoid the persistent imposition of advertising services?
I have Telegram premium, though I didn't check the privacy settings you mentioned. I will have to check it. Thanks for mentioning this. I know many people who use Telegram Premium, including those who recently got messages from unknown people. This includes campaign managers. However, I believe campaign managers keep their message options open to allow potential clients to reach them.
I recently launched my own service thread, and I am reaching out to clients from time to time. I also mention my Telegram handle in emails, so I think I will have to keep my message options open. As for other users, if they use Telegram Premium, they can use the feature you mentioned.