If you get your posts automatically deleted on Reddit, that is probably because you lack comment karma or your account is too young, or both.
Make sure you check the reddit messages as there is often an explanation from automoderator bot explaining the reason.
For example.
Thank you for your comment in but your comment has been automatically removed for low karma/account age. This is to filter out bad comments and bots. You need 2 comment karma to assist on this subreddit.
Your post has automatically been removed due to your account not meeting the minimum posting requirements. The minimum posting requirements are listed here and is at the time of writing: The account has to be at least 30 days old and have 10 comment karma. You currently meet Neither requirement. Please try posting again once you have met the minimum requirements. We do not make exceptions to this rule. The karma number on your profile page will be your combined post and comment karma. To see just comment karma, hover over the ‘i’ in a circle that’s next to combined karma, and you’ll see your breakdown. Please note that using subreddits will get you banned for an additional 7 days.