Mail Groups Unrelated Emails into Conversations

I fixed this for two people at my workplace today but I don't know yet if there are any unforeseen consequences. In any case if you want to try it yourselves do the following:

1. Open Apple Mail Preferences

2. Click on the "Viewing" tab

3. Near the bottom, uncheck the option "Include related messages"

Seems particularly prone to this with anything starting with "RE" in the subject line. Obviously that would pull in lot of messages, but it's really annoying and I can't get it fixed!

I understand that those of you who respond by saying "ungroup the messages" mean well, but it begs the question as to how Apple can fix the threading problem which groups unlike messages whose subject line happens to start with "RE:" There must be a way. I don't expect a user to solve it. I expect someone smart and interested in end-user satisfaction at Apple to solve it.

In theory, this sounds like the right setting to change, but it didn't fix a thing for my killer Conversation cluster. Still have 217 messages (and counting) log-jammed together from at least 31 unique message threads from many different individuals.

From what I've seen in other similar posts on Apple's support community, this has been happening in Mail for at least a few years. No idea what fuzzy logic they're using to determine what belongs where, but it obviously doesn't work correctly. SO STOP IT!! Relying just on identical "RE: and FW:" threads is good enough for me!

The message grouping worked perfectly in Mavericks. I 'updated' to Yosemite 10.10.1 - and this is when the feature broke.

Please report it to Apple:

http://www.apple.com/feedback/macosx.html

This is how I solved the problem : http://wp.me/p4kqiM-60

Just to say before you do this - BACK UP YOUR EMAIL!

It shouldn't be a problem if you're accessing via IMAP - but I always backup anyway. Export your inboxes & sent mail - and any local folders along with their associated subfolders.

I recall trying this a while back in many efforts to sort the problem - and it didn't work for me. I just tried again - and initially the emails grouped correctly. However on restarting they went back to their previous unrelated grouped-up mess.

Please Please Please sort this Apple... 😠

I restarted my laptop and there were no issues, mate

It will be interesting to hear from other people to see if this solved their issue. Alas it didn't for me 😟

Mail is really screwing a lot of my business related emails by groups stuff together that has no relationships to each other. Different companies, subjects, people....This is enormously frustrating for me. Does anyone have any idea how to completely shut this 'grouping' function off. I don't need Apple to do this for me and especially since they are messing it up royally.

I did a clean install of Yosemite already (when trying to resolve wi-fi issues). Now, some months later, this problem of unrelated emails getting grouped has just started for me. (I sure as heck won't be going through another clean install.)

I use POP email accounts, so I can't just delete accounts and recreate them without backups as one commenter suggested. I might wait for 10.10.3 before trying to back up and restore things. Let's hope.

Exactly the same issue here. Work is becoming a pain when I have to search for something in the gigantic thread that has been created with unrelated emails... Hope anyone can get to a solution. Thinking about switching here... I'd really hate to get back to Outlook...

Just went through an hour with Apple support taking over my iMac and essentially rebuilt the mailboxes a number of times with mild success. Ultimately took the huge thread of incorrectly grouped emails and chose some that I really needed to keep and Archived them (Mail/Message/Archive) and deleted the ones I didn't need to keep. About halfway through, the thread reorganized and everything was correctly grouped! There must have been one or two emails that had corrupted header index IDs. You might try that approach without going through all the pains of dissecting the library and deleting all the Mail files.

I just rebuilt the mailbox one by one. Seem some have been repair. I have sort the email and seperate into over 30 mailbox. I just starting and hope it could really solving on that