My understanding (my work is almost entirely email generated) is that you keep to the same email thread unless there is a drastic change of subject. You create a 'chain' in the thread.
Long distance friend, known for ages, we 'chat' by email now and then. She has however a habit if starting a new thread (sometimes I think to show off her 'wit' with a catchy subject line) almost for each email reply. This means that some of what I've written to her appears to go unread (it isn't, I know) but there is a only a brief passing comment from her.
Other friends will go through received emails in a logical way, replying to what I've said, and then adding their own news. Some, even copy and paste lines from mine and they reply underneath.
Is there any kind way I can pull her up on this without it seeming too obvious? It makes me feel she doesn't engage with my news or feelings and I really don't know why she starts a new email every time we 'talk'! No one else does this! How can I say something to make her know it seems rude?
I don't think your friend is rude at all. You seem to be expecting her to follow a corporate email convention but this is her style and as this is not in a work context then you really have no right to try and force her into what you deem acceptable. That really would com across as rude.
Having said that I can see why it would be irritating. Maybe try whatsapp instead?
I think when it’s a friendship not a business relationship, you either like them as they are or the friendship comes to a natural end. It’s a bit odd imo to want to change them. Maybe they find your emails boring?
I can’t really fathom how clicking ‘new message’ rather than ‘reply’ is rude.
If the real issue is that she is not acknowledging or engaging with any news you are telling her and her emails are all ‘me me me’ then yes, that is rude, but she’d still be like that if she hit ‘reply’ probably.
I hate creating a long email chain, at work you need to do that to create a chain of evidence. At home its a faff.
''It makes me feel she doesn't engage with my news or feelings'' I think this is the real problem. You don't think that making a brief passing comment is enough, and she does. You have a mismatch of communication styles.
It might be for practical reasons: she may have an elderly computer which struggles to download long email chains, especially if they've got bits embedded into them? She may have an iPhone where it can be quite hard to get to the latest email if there's a strand of emails? My sister and I swap emails daily, and therefore can end up with long email chains - what usually happens is that one of thinks this is getting a bit unwieldy and starts from scratch - doesn't stop us referring to previous emails.
I hate email chains as they store together in my inbox, rather than in date order and can make going back to find something tiresome, and the previous conversations get more and more indented until you cannot really read what was said anymore.
Why don’t you send more frequent messages that are shorter so she needs to reply to whatever needs it is you are telling her that you want a response from? From your OP I agree it sounds like you want her to reply to certain aspects of your email and that is the issue.
I hate long, long, long email chains too. It makes going back to look for something a pain. If she starts a new email with a title she'll be able to check back on things more easily as they'll be 'categorised' for her.
BUT if she's ignoring your news, points etc I can see that might be annoying.
I don't think I have ever hit the 'reply' option for a personal email - usually I create a new email (with 'witty' title - oops! - although in my defence it often refers back to something they've said in their email).
It can be annoying when you tell someone something you feel is interesting or important and they don't make reference to it when they reply, but I wouldn't take it too personally. It doesn't mean they haven't read your email or that they don't care. People tend to get carried away with their own news, especially if they don't see each other too often. If you want a proper two-way conversation, perhaps Messenger would be better.
It would be inappropriate to try and get her to use the same system for emailing as you - it's a bit like walking into her house and rearranging her books.