I believe its Netscape 7.. under OS 9. MITM proxy ?? I do have enabled with all my email address, use less secure apps.. Outlook Express should connect and allow me to send/receive email. Do you know the imap settings for gmail ? If I recall, I did enable use less secure, so it should work.
For Gmail under outlook read here: https://www.vogons.org/viewtopic.php?p=774999#p774999
According to my research, OE 5.0 ~ 6.0 will only "speak" TLS 1.0. To support TLS 1.1 and above one has to set up a local proxy server.
Basically I've set up stunnel running as a background service on my host machine, and the Windows 3.11 VM running OE 5.0. So the host machine acts as proxy server for your OE 5.0 to get into Gmail. This is because Gmail no longer accepts Plain AUTH. (I think).
I haven't tried it with OE and OS9 yet - but I assume the procedure will work the same way.
I do believe that since Netscape 7.0.2 is Mozilla based, it can access HTTPS with a NSS update, the same update Roytam1 did for Netscape 9.0.0.6 (and I think Retrozilla uses the same thing) on Windows 98SE. I just used that updated Netscape 9 on Windows 98 last night to get a few drivers from HTTPS websites.
This NSS update even have files with the same names and location as seen in the Netscape 7.0.2 install on my OS9. However, someone has to volunteer for the task and also need to know how to "convert them into OS9 format", because these files are DLLs for Win98 Netscape version. If we had that, then Netscape 7.0.2 could theoretically be able to access at least TLS 1.2...