I have a support@ account that is fairly low volume. I recently noticed that all new mail coming into the account was being marked as read without my intervention. I've confirmed there are no rules acting on the account. This morning, I closed my mail client, just to be sure, and sent the account a message from my phone (which does not have this account configured). In opening the account in Horde, it was already marked read. I therefore closed Webmail and sent a couple of further tests and monitored the "new" mailbox folder - in the first instance, about 10 - 15 minutes after it was delivered, the message was moved to the "cur" folder. I deleted the dovecot.* files in case something there was impacting the status, then sent another message to the account - within 5 minutes, this one was also marked read and moved to "cur".
I've checked cron and see nothing there that could affect this. I'm pretty certain this is happening on the server (ver. 8.2) but am unable to see where it might be happening. I'd appreciate any ideas on where to check this further.
Thanks,
Des