SMTP Error 235 - Authentication successful. | Warmup Inbox
The short answer
Authentication successful. Common cause: Your AUTH login was accepted.
Quick fix
You are logged in and can send.
2 - Success. Not an error - the server accepted or completed the action.
How to fix it
You are logged in and can send.
Related codes
- 211 System status or help reply.
- 214 Help reply.
- 220 Service ready.
- 221 Service closing transmission channel.
- 250 Requested action completed.
- 251 User not local; will forward.
Most rejections come back to sender reputation.
Blocklists, auth failures, and policy blocks are what warmup prevents. Warm up your domain so your mail is trusted before you hit send.