Multiple Computers Duplicate Messages

I have Spam Sieve running on a desktop that is always on but I primarily use a laptop or phone as my daily device. On the desktop Spam Sieve acts as it should. I have it filter the spam to a folder in my iCloud email account so I can check it from any device. On my laptop I can see the spam folder with all the messages in it but will also get duplicates of the same messages in my inbox as well. What am I doing wrong?

Is SpamSieve installed on the laptop as well? If so, is it running at the same time on both Macs, or do you shut down one when you use the other?

Are you using more than one mail account, or only the iCloud one?

No. I only have it running on my desktop. Should I have it running on both? I have used the desktop because it has my wife’s email setup on there too so we can filter both our accounts.

I have 4-5 accounts setup. I just use the iCloud one to put my spam from all my accounts in a place I can access easily but I’m open to better options. My wife doesn’t like to check her spam folder ;). This allows me to check it without being in her email.

No, that’s fine. I’m just trying to understand how you have it set up.

Are you saying that you can have the two Macs open side-by-side and they show different messages in the inbox? Which mail program are you using? Please make sure that all the accounts are configured in it as IMAP (or Exchange) rather than POP. POP will download all the new messages to the inbox even if another Mac has already moved them to the Spam mailbox.

That is correct. My desktop mac only shows my spam messages in the spam folder. My laptop shows those messages in the spam folder but they also still hit my inbox. I am using Apple Mail on Mojave. All of the accounts are either IMAP or Exchange.

Are you able to log into Webmail and see whether it shows the spam messages in both places?

Yes. I logged into webmail and I see the message in both places.

It sounds like the issue is that the desktop is not properly syncing it changes back to the mail server. Or perhaps the Webmail and other Mac are showing messages that have been deleted but not yet expunged. Are you also seeing iCloud spam message copies in the inbox, or only from the other accounts?