HEADER finding
Missing Message-ID header
The message has no Message-ID header. RFC 5322 requires one, and its absence is a negative signal for spam filters.
Finding code
missing_message_id
This finding appears in the findings array of
the spam checker and
the POST /v1/sender API response when the
condition above is detected.
How to fix it
The fix.
Add a Message-ID header to every outgoing message. RFC 5322 requires it, and its absence is a spam signal. Most libraries generate one automatically; if yours does not, create one before sending.
Related HEADER findings
Other things we check.
| Finding | What it means |
|---|---|
no_authentication_results
|
No Authentication-Results header |
missing_date_header
|
Missing Date header |
missing_list_unsubscribe
|
Missing List-Unsubscribe header |