NoRecipientAction |
How to handle no recipients in header | V8.7 and later |
What |
§ |
Meaning |
---|---|---|
add-apparently-to |
See this section |
Add an Apparently-To: header |
add-bcc |
See this section |
Add an empty Bcc: header |
add-to |
See this section |
Add a To: header |
add-to-undisclosed |
See this section |
Add To: undisclosed-recipients:; |
none |
See this section |
Pass the message unchanged |
The NoRecipientAction option is safe. If it is specified from the command line, sendmail will not relinquish its special privileges.
Add an Apparently-To: header. That is, act like pre-V8.7 sendmail. But note that this choice has been deprecated and should not be used.
Add an empty Bcc: header. This makes the header portion of the mail message legal under RFC2822 but implies that all recipients originally appeared in Bcc: header lines. But be aware that old versions of sendmail will strip all Bcc: headers, so the next site might add an Apparently-To: header and wrongly expose the address.
Add a To: header and fill it out with all the recipients from the envelope. This can be misleading because it can give a false picture of the intended recipients. It can also cause Bcc: header addresses to be mistakenly revealed. This choice might be appropriate in the command line when sendmail is run from an MUA that routinely omits recipient headers.
Add a To: header, but list in it only the address of an empty, but descriptive, mailing list:
To: undisclosed-recipients:;
This is the recommended setting for use in configuration files.
Pass the message unchanged. Currently, this is technically illegal because RFC2822 requires at least one recipient header in every mail message. This choice might be appropriate for naïve sites that kick all mail to a smart host for processing. Note that RFC822 makes this legal.