C-Command Software Forum

Using Desktop as "pre-filter" for notebook

Based on a suggestion that was made just after the iPhone came out, I have set up the following scenario to minimize the amount of spam I receive on my notebook:

Home desktop, running 10.4.11, mail.app:
Have an IMAP account called “Spam Catcher” that processes email every 5 minutes, and uses SpamSieve to move Spammy messages to a local “SPAM folder”, leaving all other messages in the InBox. Seems to work well, catches almost 1000 messages a day.

Notebook, running Leopard 10.5.2, mail.app as well
POP3 account that processes email every 15 minutes, and uses SpamSieve to move Spammy messages to local SPAM folder. My intent was that this would only be messages that “sneak through” the Spam Catcher (timing issues). I’m catching a lot of “duplicates” from the Desktop.

Here’s my question: I’m noticing a lot of identical messages in the SPAM folders on BOTH machines which makes me think that on the Desktop SpamSieve isn’t actually “moving” them from InBox folder to the SPAM folder, but somehow leaving them in the InBox.

I’m not sure that’s what’s really happening, but why would the same exact SPAM messages be in both SPAM folders (based on “View Raw Source”). Can you think of any reason why the Desktop didn’t remove these messages from the InBox properly? Maybe a timing issue?

TIA for any advice… :slight_smile:


It sounds to me like a simple timing issue. Your notebook sees the message before the desktop does. Then, either the notebook doesn’t remove it from the server (not sure whether you have Mail set to do that), or else the desktop sees it before it’s been removed from the server.

That is the source of my confusion. Both instances of SpamSieve are set to move all spammy message to a SPAM folder that is “local”, not online, and the appropriate switches are set in both versions of mail.app. In my mind, which-ever machine sees it first should “remove it from the server”. But this is not happening.

I had an issue a couple years back where I was using SpamSieve locally on only my notebook, and noticed that my /var/mail/sparker file on my web host was HUGE, and full of spam that had been “moved to spam” by Spamsieve. I never did get that worked out.

What I’m going to try next is to move spammy message to the trash rather than to “spam” and see if that movement will remove them from the server. After all, all I do with the Spam folder is look through it for false positives before trashing it anyway, and I can look through the trash just as easy as through a Spam folder.


Consider this timeline:

  1. Notebook downloads message.
  2. Desktop downloads message.
  3. Notebook deletes message.
  4. Desktop deletes message (error because it’s already deleted).

With this interleaving, both Macs will end up with a copy of the message even though it does eventually get removed from the server. Basically, I think the problem is that you are attempting to use IMAP and POP to do something that they were not designed to do. The server doesn’t prevent another client from downloading the message after the first client has downloaded it and is deciding what to do.

It’s important to remember that SpamSieve doesn’t move any messages. You have a regular Mail rule whose action is to move the messages, and Mail does the moving. The only difference is that SpamSieve determines whether the rule’s criteria are met. Whether the messages end up being deleted is entirely an issue with Mail and/or your mail server. In my experience, Mail’s “Remove copy from server after retrieving a message” “When moved from Inbox” setting only applies to messages that were moved manually, not by rules. If you want the messages to be moved from the server automatically, you need to select “Right away.”


Thanks for all the info (and for the most useful “behind the scenes” program I have installed on my Mac). I understand the Interleaving problem (when they’re both processing at the same time. Hopefully that will get hit “rarely”, but I do understand it’s possible.

As for the Remove from server, I missed the “Right Away” setting, which I now have set on the POP3 side. If what you’re saying is really true (about manually moving is the only way to have messages removed, not with rules), then what I’m trying to do is indeed futile. I’ll have to come up with a better process… If I do, I’ll post it here…