I changed the default behaviour of grouping messages , by change the value of the zimbraMailThreadingAlgorithm param from "references" to "subjrefs" .
I reindex the mailbox by : zmprov rim [xx@xxx] start
but nothing change : mails grouped by reference but with different subject are still grouped .
according with this https://zimbra.github.io/adminguide/8.8 ... _threading they should split in differrent conversation ,but they don't
any suggestion?
thank's
Release 8.8.15.GA.3829.UBUNTU16.64 UBUNTU16_64 FOSS edition, Patch 8.8.15_P26.
references — the same logic as "strict" with the constraints slightly altered so that the non-standard Thread-Index header is considered when threading messages and that a reply message lacking References and In-Reply-To headers will fall back to using subject-based threading.
subjrefs — the same logic as "references" with the further caveat thatchanges in the normalized subject will break a thread in two.