3 Matching Annotations
  1. Dec 2020
    1. To expand an alias, the recipient mailer simply replaces the pseudo- mailbox address in the envelope with each of the expanded addresses in turn; the rest of the envelope and the message body are left unchanged. The message is then delivered or forwarded to each expanded address.

      This annotation explains what this paragraph means and dispels my confusion regarding how 3mails with multiple recipients will get processed (also, SMTP envelope vs mail data).

      MS Outlook's "distribution list" is the same as an rfc5321 alias.

    2. If the Klensin Standards Track [Page 19] RFC 5321 SMTP October 2008 recipient is known not to be a deliverable address, the SMTP server returns a 550 reply, typically with a string such as "no such user - " and the mailbox name (other circumstances and reply codes are possible).

      Will the entire transaction be canceled? "Transaction" in the name of this a section implies yes, but what if all the recipients are valid?

      See replies below but the answer is no; an RCPT command is specified for each recipient in the mail data, these RCPT commands will be evaluated in sequence,, and any SMTP (error) notifications will be sent to the address in the MAIL FROM command (which is not necessarily the same as the mail data's From: header).

    3. The second step in the procedure is the RCPT command. This step of the procedure can be repeated any number of times.

      This step of the procedure can be repeated any number of times. !

      So the section

      3.9.1. Alias

      To expand an alias, the recipient mailer simply replaces the pseudo-mailbox address in the envelope with each of the expanded addresses in turn; the rest of the envelope and the message body are left unchanged. The message is then delivered or forwarded to each expanded address.

      means that for each "to:" rfc822 message header in the mail data (i.e., SMTP envelope's DATA) a RCPT TO command will be added.