My mailserver time went out of sync.. it was a day in the future, so I quick changed the time back to current and immediately scalix froze up. I restarted scalix only to find about 5-6 users started to have problems with missing emails and IMAP UID errors (Outlook reports an invalid UID of 0 for hundreds of emails in their inbox).
I changed the time back to the future, and the missing email reappeared. The UID problem persisted, and I fixed it by creating new accounts and imapsync'ing their mail into new mailstores.
Is this a known issue? Has the UID issues been resolved in latest release? I am still running 11.0.0.344-beta, and I plan on updating to the latest 11 release as soon as I can.