[n5bb]

Originally Posted by BritTim

...By the way, what do you want to happen if the message is to both one of the rejected addresses and one of your good addresses? If you still want to reject delivery, you probably need the sieve solution with all its complexity. If you want delivery to the good address to occur, your current custom sieve is broken.

This can get complicated.

• If a single email is sent with several of your addresses (possibly including blocked aliases) in the To, Cc, and/or Bcc sending fields, the message is typically split into multiple messages and these are individually delivered to your account.
  • Messages sent to your account main address are by default targeted for delivery to your Inbox folder.
  • Messages sent to an alias are by default targeted for delivery as specified by the alias table entry. This is normally Inbox, but can be modified to any other folder. For example, the target could be set to username+test @ fastmail.com, and multiple internal or external targets can be used. So you could specify that three copies of all messages sent to that alias are delivered to three separate folders.
  • Sieve can change the target delivery folder, forward the message, or discard the message.
• If the message was sent to three addresses (two normal and one you wish to block) using the To and/or Cc addressing fields, three nearly identical copies (with identical To and Cc fields as specified by the sender) are potentially delivered to your account (if none are rejected aliases).
  • One has the X-Delivered-to header set to one of the normal addresses and is delivered to the folder specified by the alias target. This can be overridden by sieve to any other folder, or sieve can block this copy of the message based on To, Cc, or X-Delivered-to.
  • The other has the X-Delivered-to header set to the other normal address and is delivered to the folder specified by that first alias target. This can be overridden by sieve to any other folder, or sieve can block this copy of the message based on To, Cc, or X-Delivered-to.
  • If there is no alias block, the third "bad" message has the X-Delivered-to header set to the address you wish to block and is delivered to the folder specified by that second alias target. Sieve can block this copy of the message based on To, Cc, or X-Delivered-to.
  • If the "bad" message is blocked by an alias marked to reject, that message is never received at your account.
  • If the "bad" address was in the To or Cc field, the two normal address copies could be blocked by sieve script which noticed the address you want to block.
  • If multiple identical copies of the same message are delivered to the same folder (or Inbox) at your account, normally only one copy will remain, and the others are discarded. This is controlled by the Duplicates setting in the Advanced settings for a folder.
  • But if the "bad" address was in the Bcc field when sent, the two normal address copies won't contain any mention of the "bad" address, so they can't be blocked. This is true no matter how you try to block the bad messages.
    

Bill