In Opera\mail\store\account I have all my mails from 2010 january on.But the current view only shows the mails from the last 2 years ( 2014 till now ). How can I retrieve the older ones when needed ? The retrieving does not need to be permanent, but just that I can have a look when needed.
Thanks for your help and advice !

But OK ! I found them indirectly

I'm sorry,@Burnout426, but these 2 reddit-pages do not seem to exist

Due to a haphazardous corruption of my WIN 10 - profile, I could no longer enter my Opera email account. In trying to resolve the matter one way or another my email database index ( with 70.000+ messages ) went also bezerk !!! I still have all .mbx & .adr files. on disk. But searching the database for either a contact, a term or a date gives totally erroneous results ! How can I repair this ?
I know I'm a bit crazy to stick with Opera mail, but after all those years and all those crashes, I still am used to and appreciate this whacky program

Well, first of all, thank you so much burnout426 ! Sure you're not yet burned out ! It seems to work smoothly now - except for the one tricky problem that is handled in another thread.
What did I have to do :
1- delete the newly created folder in "C:\Users\user\AppData\Local\Opera Mail\Opera Mail".
2- Put the mail root directory line under the [Mail] section in a operaprefs.ini, rather than under "Users preferences "as I did first.
All other conditions were OK. And my E-drive is a 500GB partition on a big 2T HDD.

Thanks again and see you at the next problem

I did move "C:\Users\myName\AppData\Local\Opera Mail\Opera Mail\mail" to E:\Opera . So there was no longer this file in C:
and put "Mail Root Directory=E:\OPERA\mail" in operaprefs.ini
Starting operamail then opens the wizard new account ! But I do not want a new account !!!
What went wrong ??

Thx

"Have you edited the file with Opera closed ? " Of course
"You were able to save it ?" Yes. The file before editing was 2691 b; after editing it was 2777 b. But at the very moment Opera mail is started the file defaults to 2691 b,

This one ( rather Short ) message is still in the outbox while I had no one problem in sending some 10 other and different messages.
Thinking of it : the 2 messages that got stucked in the outbox were 2 'forwards'.

I'm now a Opera users since way more than 15 years and I keep wondering why it is that each "upgrade" time and again comes with bugs and problems. Why always change a winning team without toroughly checking it out first ??? I was quite happy with the combined browser-mail client that I used the last couple of years. And all of a sudden, with this bloody "automatic upgrade" I'm in the sh*t ! No longer is the mail combined with the browser, but there is this idiosyncratic error !!
I think of downgrading to the previous client, but that is again a lot of work. And I'm not sure that it will be fluent, because I changed to a new PC and OS ( Win 7 => Win 8 ). Greetz.

@leocg who said "It's in accounts.ini. You need to add the line Outgoing Log File=X:\Path-to-Folder\logfile.txt."

To no avail. This added line is automatically deleted when starting Opera mail
@burnout : I therefore cannot check what might have happened,

Sending the message to another adres is no problem. And the original address is abolutely without errors and in use since years.'

Thx for comments.
@sgunhouse : sure it is on my end. The last message is still in the outbox after 24 hrs.
@burnout : I'll try and follow suit. Thx.

" Maybe it was typed wrongly? "

Not at all. I used copy/paste.

And today, another message, quite small to but 1 address , again stays put in the outbox and cannot be sended.