Mail: Organize By Conversation - wrong emails

I also regularly move emails between Exchange and Gmail accounts, in order to archive them the way this works best for me.

If more people having this problem are doing this, then it might be a possible cue for the developers to find this bug.

I am suffering exactly the same problem - completely unrelated messages are being grouped together when Organize By Conversation is checked. It's grouping together emails with different senders and different subject lines.

I've used this feature since it was introduced and have found it enormously useful, but something has happened in the past few days that has rendered it completely useless! I haven't changed any settings or touched anything.

Hello...Apple?

This is a major issue. I have a 1,120 message thread with upwards of 15-20 combined conversations.

Dear all,

Discovered this discussion on incorrect mail grouping. Have the same issue and nothing seems to help (unchecked related messages). I just don't get it. We've seen 10.10.2 being rolled out and this upgrade never addressed this particular problem. But what boggles my mind is that this showed up after I upgraded to Yosemite! Been through Snow Leopard, Lion and Mountain Lion, but it wasn't until Yosemite that this **** threading problem surfaced. Having serious regrets about that decision now. I am firmly hoping a solution will not be long in the making. Apple, please step up to the plate!

We lost three months

This is affecting me as well.

When are we going to get a fix for this problem?

Come on Apple, we're waiting...

Have logged this and provided data to Apple. My bug was closed as a duplicate of 18454172. Does anyone know if there's any way to see but 18454172?

I'm having the same problem, even though I'm still using Mavericks (10.9.5). It's suddenly appeared in the last few days and makes the search function useless—when I search for one correspondent, it turns up hundreds of messages from totally unrelated people.

I reindexed my mailboxes and it seems to have sorted the conversation issue and an issue with Mail taking a very long time to shut down. We'll se if it lasts.

Hi Redfish8553

When you say "reindexing" is that the Mailbox > Rebuild command?

Or do you mean something else?

No, it was deleting the files that begin with Envelope Index in the Library under mail. http://osxdaily.com/2013/08/01/rebuild-mailbox-reindex-messages-mail-mac-os-x/. other references to this in support. It took about 10 minutes to reindexed 90,000 messages. I did drag the old index files to my desktop in case something went awry and I did have a fresh backup.

Hi redfish8553

And this procedure solve (in your case)

Best Regards

I also tried reindexing, but it didn't work for me. It looked like it was working at first, but mails eventually started grouping again.

I'm pretty sure this bug is indexing related, though.

I think it is indexing related since it did change the grouping. I compared the size of the files and one of the old envelope index files was significantly larger than the new one. Not sure what that means but it could be that the file becomes corrupted over time. Just a guess. That could be why reindexing only works for a period of time. In any case, it also cleared up my issue with impossibly slow quits in Mail. Also notice that some people like to continually respond to old emails rather than start new ones. That can make it look like a grouping issue.

i've been putting off upgrading to the latest version of yosemite for a few weeks. finally got around to doing it last night, and now today i'm experiencing this error in mail. aside from being disconcerting seeing random e-mails grouped together (clients, friends, strangers…yikes!), it's also affecting productivity.

it seems like this issue has persisted for a while — surprising and frustrating.