This usually happens because new accounts on X don’t have enough trust yet. Even if you’re sending messages manually, the platform still looks at patterns like sending many DMs in a short time, messaging people who don’t follow you, and similar message structures. Around 30 to 50 DMs is often where new accounts start getting flagged.
Cold outreach is especially sensitive. If most of your messages go to people who don’t reply, the system assumes spammy behavior. Premium doesn’t really remove this, it just raises limits slightly. Account age, replies, and normal activity matter more.
What usually helps is warming up the account first. Post normally, reply to tweets, get a few conversations going, and slowly increase DM volume over a few days. Spreading messages across longer time gaps also reduces flags.
Another thing is message similarity. Even “customized” outreach can look templated if the structure is the same. Changing tone, length, and opener helps. Some people even draft varied outreach angles using Runable so the messages don’t follow the same pattern.
In short, nothing is wrong with your account. It’s just a new account sending too many unsolicited DMs too quickly, which triggers spam protection.