smtp bounce code
554 5.7.1Message rejected as spam
what to do
Keep the address, fix your side
Content or reputation refusal. The mailbox is almost certainly real and reachable by someone with a better sending reputation.
What the server is telling you
The server evaluated the message or the sender and declined it. This is a judgement about you, not a statement about the recipient.
Next steps
- →Keep the address.
- →Check blocklists for your sending IP and domain.
- →Warm the domain properly before sending at volume.
Commonly returned by: Most filtered domains
Find these before you send, not after
Paste a list and see which addresses sit on domains that accept no mail, which are one character from a real inbox, and which are on catch-all domains where nothing can tell you anything. Free, no signup, nothing stored.
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