I have 4 Imap accounts and one exchange account. Most of them integrate well with spamsieve in Airmail - all their spam goes into a single spam folder.
The apple mail account however has it’s own spam folder and its own spam. I would love to have all the spam in one folder. Any idea why this is happening?
Airmail puts the SpamSieve spam into the mailbox designated (in Airmail’s Accounts > Mapping preferences) for Spam. If you select the iCloud Spam mailbox there, all the spam should end up in the same place.