Nextcloud 20.05 Email Access via IMAP not displaying previously read messages

Good Day. I have configured the NC integrated email client to access my IMAP based email services. Noticing that messages that I might have viewed previously in another email client (i.e. on a mobile device) are not showing up in the NC client inbox. Any thoughts as to why this might be? The messages are still in my IMAP inbox when I view them in other mail clients. Just not showing up in the NC client. TIA

I don’t have a solution for your “integrated mail app” but i can confirm, that in my own home network the mail client of nextcloud never did what i would expects it should do.

So in my case i switched to the rainloop app and we are very pleased with that. Everything is working as expected and very comfortable on top. The look and feel of the rainloop app seems far more sophisticated (in my opinion) than the (integrated) mail app has ever been.

If you want to give it a try you might be happy as well.