Free mail client with "mark mail as read manually" option on macOS Sonoma?

Question

I am looking for a free email client that has a "mark mail as read manually" option.

Back on macOS Ventura, I used to use the Mail Act-On plugin with Apple's native Mail app. This plugin had an option to mark mail as read manually, so if I accidentally selected an email, it wouldn't be marked as read unless I manually decided to mark it as such. Although Mail Act-On was a paid plugin, this small feature was free to use.

However, with macOS Sonoma, this feature is no longer available due to Apple's discontinuation of traditional Mail app plugins.

Is there any way for me to view my email without having it marked as read automatically on macOS Sonoma without paying an arm and a leg?

One option is using Mimestream, which seems to have a "mark mail as read manually" setting. However, it costs $50 a month.

Another option is to use the side panel in Gmail, which yields the same outcome. However, it's hard to keep track of almost 10+ accounts this way, and it only works for Google mail.

Answer 1

Assuming that no such software exists within the criteria:

I presume you're using the Read status as some kind of "Needs Action" flag, and you only manually clear the Read flag when the email has been dealt with?

Perhaps use one of the other Flags for this purpose? You could create a Rule to flag every incoming email, and then manually remove the flag when dealt with.