How do I prevent all email messages in a conversation being included when I reply or forward one?

When you select a message in the list, all conversations messages appear in the viewer list. Click on the one in the viewer you want and it will highlight that one and you should notice the rest are not highlighted. Hit reply and only that message will be replied to.

You can do the same to delete certain messages in a conversation also.

You can go to Mail>Preferences>Composing> and there in the "Responding" section set what exactly you do and do not want included in your Replies:

Hope this helps 🙂

The others should not be included. Are you saying that more than one message is sent out, or that the text is included from all messages in the reply of the email? If it is an issue about all text included, see Radiation Mac's post. Check the bottom box to include selected text. Then you can select specific text in a message body and hit reply or forward and only that text will be included.

If you select the box and selecting specific text in a message and hit reply doesn't work, then your Mail preferences may be corrupted. Try unselecting the last box, quit Mail then reselect the box to use selected text. Quit Mail again and reopen it. Make sure that box remains checked. If it still doesn't work, it might require more drastic measures of deleting Mai's .plist preference file to correct the issue.

Also, have you tested it on a message that doesn't have a conversation involved?

Have you tried it on a non conversation message to select specific text and reply? What happens there?

I assumed your problems were not account specific. Are you saying gmail works fine in all aspects and iCloud is what you have problems with?

I don't think we are understand the problem correctly, but seems to be a bit clearer now. The box to "Quote Text from the Original Message" should not be checked. If it is, uncheck it. If it isn't checked, then try what I said before by changing the selection, quit Mail, open Mail and uncheck the selection again. Quit Mail and go back and make sure the box is still unchecked. If it doesn't work, the .plist file may be corrupt and will require further action.

You can also test that by creating a test user account, log into it and create the account there and test it. That will verify a corruption problem in your user account.

The only way to have only the most recent text from the last message is to select the text you want and then reply. Conversation view always includes in each message the ongoing conversation from all previous messages when the Quote Text box is checked. If you look carefully at each message in the view, you will see a selection text at the bottom left to show more and expand the message fully. That will expand it to show all text included from below. If it doesn't work that way at the gmail site, it's because that probably have a setting to include only text from the most recent message that Mail is not capable of.

Even if you don't use conversation view, all continued conversations to a message will contain all text until you change that manually by deleting what you don't want in the next message.

If there is another solution to change it, I don't know of it. You can also quickly highlight the portions in the message body you don't want and delete it. I find it works about as well and fast as selecting specific text depending on the message and what I want to keep in it.

For rules, remember that they apply only to new incoming messages to the Inbox. If they are read on another device first, then they will download to the computer where the rules reside and be shown as read. The rules won't act upon them. Also remember that rules are applied in the order of the list. Make sure no rule above or below affects message rule that isn't working like you expect.

For iCloud vacation response, that is set at the website. If you have problems with an iCloud account, maybe something got corrupt. The only action to fix that is to sign out of iCloud via system preferences. This will remove the account from Mail and will remove the files from the computer. Signing back into iCloud will recreate the account and fresh files on the computer. It usually fixes any iCloud problems.

Good Luck