Hi David.

I am surprised that you used to use these addresses in separate accounts. I believe that they are not separate accounts at Proton, but aliases for one account. Do you have three separate accounts in webmail at proton.com or just one? Does mail sent to any of these addresses go to the one, same account at proton.com or different accounts there?

I believe that you have set up the same account three times in Thunderbird.

You might find benefits in using one account in Thunderbird, identities, and a message filter to file incoming mail by alias into separate sub-folders of your inbox.

You could check my understanding by looking at help information on proton.com.

I found that in setting my Thunderbird client, I didn't specify SPLIT

I found that in setting my Thunderbird client, I didn't specify SPLIT

Where is this SPLIT function within Tbird Settings (ie Servers Settings, Copies & Folders, etc) ? I'm using very old version 60-9-1 so they might have added that in a newer version.

My protonmail account (paid) gives me 6 different emails and each has its own Settings in Thunderbird.

What is SPLIT?

I am still curious. Aren’t all three addresses associated with the same account? Aren’t two of them aliases?