I use old Opera: today when I open Gmail it redirects automatically at HTML version saying that I'm using a not more supported browser. In Google Support there is a link to switch Gmail to the normal version, but if I close Gmail and later I open it again it redirects me again ! Which is the problem for Gmail and Google ? It's possible to see Gmail in normal version every time I use the link ! Google want only that I switch to Chrome ?
When you say 'old Opera' do you mean Presto Opera? You might be able to fool Gmail by changing/spoofing your user agent. I had to do this with K-Meleon.
IIRC you can put a customised version of your user agent into Opera Presto rather than a preset. I could be wrong though.
Try this. Open override.ini and in the [Overrides] section add this: mail.google.com Then add at the end of the file add: [mail.google.com] User Prefs|Custom User-Agent=Mozilla/5.0 (Windows NT 6.1; WOW64; rv:32.0) Gecko/20100101 Firefox/48.0 Opera 12.18 Maybe you should also add-repeat everything for accounts.google.com, not sure, probably not.
Nothing Google does surprises me anymore. I use 3 or 4 Gmail as garbage addresses. For real email I use Thunderbird and my ISP servers.
It's a browser from 2012. HTML5, Javascript and its libraries improved (or at least changed) significantly since 2012.
I can't remember either. https://dev.opera.com/blog/opera-user-agent-strings-opera-15-and-beyond/ This link may help.
I too use my ISP email on my pc for my private life. But I use Gmail for my work emails, only as Webmail, so I can read it easy wherever I am.
I obviously know it, but I love Opera 12 appearance and his options, and I can't find a newer browser to replace. Not Vivaldi, not Firefox..... For the sites that Opera 12 can't see I use new Opera.
You don't use Everything (or similiar)? It can search your whole disk in seconds: https://www.voidtools.com/