| Header field name |
Description |
| Abuse-Reports-To |
E-mail address for reporting abuse |
| Also-Control |
Usenet control message and a normal article at the same time |
| Alternate-Recipient |
Controls whether the message may be forwarded to alternate recipients |
| Apparently-To |
Recipients derived from message envelope when there is no To header |
| Approved |
Moderator of the Usenet newsgroup, or marks certain control messages |
| Approved-By |
Moderator of a mailing list, who approved the message |
| Article-Names |
Reference to specially important articles for a particular Usenet newsgroup |
| Article-Updates |
Similar to Supersedes but does not cause the referenced article to be physically deleted |
| Autoforwarded |
Has been automatically forwarded |
| Auto-Forwarded |
Misspelling of Autoforwarded |
| bcc |
Recipient(s) not to be disclosed to other recipients ("blind carbon copy") |
| cc |
Secondary, informational recipient(s) |
| Comments |
Text comments added to the message |
| Content-Alias |
Used in addition to Content-Location if this content part can be retrieved through more than one URI |
| Content-Alternative |
Information on where an alternative variant of this document might be found |
| Content-Base |
Base to be used for resolving relative URIs within this content part |
| Content-Class |
Type information of the content in some class hierarchy |
| Content-Conversion |
Whether the body may be converted from a charset to another |
| Content-Description |
Description of a particular body part of a message |
| Content-Disposition |
Whether MIME body part is to be shown inline or as an attachment; may also suggest a file name |
| Content-Features |
More detailed information about the Content-Type |
| Content-ID |
Unique ID of one body part of the content of a message |
| Content-Identifier |
A text string which identifies the content of a message |
| Content-Language |
Code for natural language used in the message |
| Content-Length |
Size in bytes of the message text |
| Content-Location |
URI with which the content of this content part might be retrievable |
| Content-MD5 |
Checksum of content |
| Content-Return |
Whether the content of a message is to be returned with non-delivery notifications |
| Content-SGML-Entity |
Information about the SGML entity declaration corresponding to the body |
| Content-Transfer-Encoding |
Coding method used in a MIME message body |
| Content-Type |
Data type and format of content |
| Control |
On Usenet, indicates a control message |
| Conversion |
Whether the body may be converted from a charset to another |
| Conversion-With-Loss |
Whether the body may be converted from a charset to another if information will be lost |
| Date |
The time when the message was written (or submitted) |
| Delivered-To |
Used for loop detection |
| Delivery-Date |
The time when a message was delivered to its recipient |
| Discarded-X400-IPMS-Extensions |
X.400 IPM extensions which could not be mapped to Internet mail format |
| Discarded-X400-MTS-Extensions |
X.400 MTS extensions which could not be mapped to Internet mail format |
| Disclose-Recipients |
Controls whether recipients are to be told the names of other recipients |
| Disposition-Notification-Options |
Options for notifications to be sent when the message is received |
| Disposition-Notification-To |
Requests for notification when the message is received, and specifies the address for them |
| Distribution |
Limitation on where the Usenet article can be distributed |
| DL-Expansion-History-Indication |
Trace of distribution lists passed |
| Encoding |
Mixed usage: content type encoding, length, or boundary information |
| Errors-To |
Address to which notifications are to be sent and a request to get delivery notifications |
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| Expires |
Suggested expiration time |
| Expiry-Date |
Time at which a message loses its validity |
| Fax |
Fax number of the originator |
| Fcc |
Name of file in which a copy of the message is stored |
| Followup-To |
Usenet group(s) to which followups to the article should be sent |
| For-Approval |
Primary recipients, who are requested to approve the information in this message or its attachments |
| For-Comment |
Primary recipients, who are requested to comment on the information in this message or its attachments |
| For-Handling |
Primary recipients, who are requested to handle the information in this message or its attachments |
| From |
Author(s) or person(s) taking responsibility for the message |
| Generate-Delivery-Report |
Whether a delivery report is wanted at successful delivery |
| Importance |
A hint from the originator to the recipients about how important a message is |
| In-Reply-To |
Reference to message which this message is a reply to |
| Incomplete-Copy |
Body parts are missing |
| Injector-Info |
Information about article's injection to Usenet |
| Keywords |
Keywords to be used as an aid in determining if the message is interesting to the reader |
| Language |
Code for natural language used in the message |
| Lines |
Number of lines in the body of the message |
| List-Archive |
URL to use to browse the archives of the mailing list |
| List-Digest |
URL to use to subscribe to the digest version of the mailing list |
| List-ID |
URN of the the mailing list expander |
| List-Owner |
URL to use to send E-mail to the owner of the mailing list |
| List-Post |
URL to use to post to the mailing list |
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| List-Software |
Information about the software uses in the mailing list expander |
| List-Subscribe |
URL to use to subscribe to the mailing list |
| List-Unsubscribe |
URL to use to unsubscribe the mailing list |
| List-URL |
URL for various information about the mailing list |
| Mail-Copies-To |
Special address for copies of posted followups |
| Mail-Reply-Requested-By |
Address to which notifications are to be sent and a request to get delivery notifications |
| Mail-System-Version |
Client software used by the originator |
| Mailer |
Client software used by the originator |
| Mailing-List |
Information about mailing list |
| Message-ID |
Unique ID for the message |
| Message-Type |
Indicates that this is a delivery report gatewayed from X.400 |
| MIME-Version |
Specifies the version of MIME that the message format complies with |
| Newsgroups |
Usenet group(s) to which the article was posted |
| NNTP-Posting-Date |
Time of posting to Usenet |
| NNTP-Posting-Host |
Host that posted the article to Usenet |
| NNTP-Posting-Time |
Time of posting to Usenet |
| NNTP-Proxy-Relay |
Host that relayed the message to Usenet |
| Obsoletes |
Reference to previous message being corrected and replaced |
| Organization |
The organization to which the sender belongs, or to which the machine belongs |
| Original-Encoded-Information-Types |
Which body part types occur in this message |
| Original-Recipient |
Original recipient information for inclusion in disposition notifications |
| Originating-Client |
Client software used by the originator |
| Originator |
Used the same way as Sender |
| Originator-Info |
Information about the authentication of the originator |
| Path |
List of MTAs which the (Usenet) message has passed |
| Phone |
Phone number of originator |
| PICS-Label |
Ratings label to control selection (filtering) of messages according to the PICS protocol |
| Posted-To |
Newsgroup to which the message has been posted /td>
|
| Precedence |
Mixed usage: priority value, control of automatic replies or return-of-content faciliries, prevention of mailing list loops |
| Prevent-NonDelivery-Report |
Whether non-delivery report is wanted at delivery error |
| Priority |
Priority for message delivery |
| Read-Receipt-To |
Address to which notifications are to be sent and a request to get delivery notifications |
| Received |
Trace of MTAs which the message has passed |
| References |
In E-mail: reference to other related messages; in Usenet: reference to replied-to-articles |
| Replaces |
Specifies previous message being corrected and replaced |
| Reply-By |
Latest time at which a reply is requested |
| Reply-To |
Suggested E-mail address for replies |
| Resent-bcc |
The bcc of a forwarded message |
| Resent-cc |
The cc of a forwarded message |
| Resent-Date |
The Date of a forwarded message |
| Resent-From |
The From of a forwarded message |
| Resent-Message-ID |
The Message-ID of a forwarded message |
| Resent-Reply-To |
The Reply-To of a forwarded message |
| Resent-Sender |
The Sender of a forwarded message |
| Resent-Subject |
The Subject of a forwarded message |
| Resent-To |
The To of a forwarded message |
| Return-Path |
Data passed from MAIL FROM: envelope |
| Return-Receipt-Requested |
Address to which notifications are to be sent and a request to get delivery notifications |
| Return-Receipt-To |
Address to which notifications are to be sent and a request to get delivery notifications |
| See-Also |
References to related articles (other than precursors) in Usenet |
| Sender |
The person or agent submitting the message to the network, if other than shown by the From header |
| Sensitivity |
How sensitive it is to disclose this message to other people than the specified recipients |
| Speech-Act |
Speech act categorization of the message |
| Status |
Status of delivery for the message when stored |
| Subject |
Text that provides a summary, or indicates the nature, of the message |
| Summary |
Short text describing a longer article |
| Supersedes |
Specifies previous message being corrected and replaced |
| Telefax |
Fax number of the originator |
| To |
Primary recipient(s) |
| Translated-By |
Mailbox of the person who made the translation |
| Translation-Of |
Reference to a message which the current message is a translation of |
| User-Agent |
Client software used by the originator |
| X-Abuse-Info |
Information for reporting abuse |
| X-Accept-Language |
Language preference(s) |
| X-Admin |
E-mail address of news server administration |
| X-Article-Creation-Date |
Time of original creation of the article |
| X-Attribution |
The name under which the sender would like to appear in attributions when the message is quoted |
| X-Authenticated-IP |
Apparently the IP address of the host of the sender |
| X-Authenticated-Sender |
Apparently some identification of the sender |
| X-Authentication-Warning |
Some warning |
| X-Cache |
Information about caching server software |
| X-Comments |
Comments, usually some disclaimer |
| X-Complaints-To |
An E-mail address for sending complaints on the adequacy of the Usenet message |
| X-Confirm-reading-to |
Address to which notifications are to be sent and a request to get delivery notifications |
| X-Envelope-From |
Sender, as extracted from the envelope |
| X-Envelope-To |
Recipient, as extracted from the envelope |
| X-Face |
Picture of sender's face (a 48×48 bitmap) |
| X-Folder |
Folder for saving the message |
| X-Http-Proxy |
Information about using Deja for posting, including the sender's IP address |
| X-Http-User-Agent |
Web browser used for posting |
| X-IMAP |
UID as defined in IMAP |
| X-Last-Updated |
Time of most recent update |
| X-List-Host |
As List-Software |
| X-Listserver |
As List-Software |
| X-Loop |
Used for loop detection |
| X-Mailer |
Client software used by the originator |
| X-Mailer-Info |
URL for info about client software used by the originator |
| X-Mailing-List |
Information about mailing list |
| X-MIME-Autoconverted |
Information about conversion of this message on the path from sender to recipient |
| X-MimeOLE |
Information about client software used by the originator |
| X-MIMETrack |
Info about the message passing through a router |
| X-MSMail-Priority |
Yet another priority indication |
| X-MyDeja-Info |
Internal user id |
| X-Newsreader |
Cient software used by the originator |
| X-NNTP-Posting-Host |
Posting host |
| X-No-Archive |
Do not archive the message in publicly available archives |
| X-Notice |
A comment on reporting abuse |
| X-Orig-Message-ID |
Original Message-ID |
| X-Original-Envelope-From |
E-mail address of original sender |
| X-Original-NNTP-Posting-Host |
Name or IP address of the original posting host |
| X-Original-Trace |
Information (host, time, etc.) about the original posting |
| X-OriginalArrivalTime |
Time when the message was delivered into the message transport system |
| X-Originating-IP |
Apparently the IP address of the host of the sender |
| X-PMFLAGS |
Internal flags indicating message status |
| X-Posted-By |
Attempted identification of the sender |
| X-Posting-Agent |
Client software used by the originator |
| X-Priority |
Priority for message delivery |
| X-RCPT-TO |
Indication of recipient on the SMTP envelope |
| X-Report |
Information about reporting abuse |
| X-Report-Abuse-To |
Information about reporting abuse |
| X-Sender |
Used similarly to Sender but often indicating that you may not be able to send E-mail to this address |
| X-Server-Date |
Some time denotation |
| X-Trace |
Information about posting |
| X-UIDL |
Unique ID for the message, local to a particular local mailbox store |
| X-URI |
Sometimes used with the same meaning as Content-Location, sometimes to indicate the Web home page of the sender or of his organisation |
| X-URL |
Similar usage as X-URI |
| X-X-Sender |
Similar to X-Sender |
| X400-Content-Return |
Possible future name for Content-Return |
| Xref |
Identification of a message within a server |
