KMail is irretrievably broken

[Peter Humphrey]

On Thursday, 14 September 2017 10:04:05 BST you wrote:
> A thought: what are your retrieval settings? When I create a new "account"
> I always start by setting them to "on demand" and caching for a
> reasonable short time, or the shortest possible time if it's a local
> resource. For an account holding only archive folders I'd also opt not to
> include it when checking for mail.

I have "Include in manual mail check" and "Switch off-line on KMail 
shutdown" set, but not "Check mail on startup."

My accounts number three: a POP3 account to handle my Internet mail; another 
one for LAN mail from a local server; and the obligatory local folders. 
Occasionally I play with an IMAP account for gmail, but my ISP doesn't offer 
IMAP. There's never anything in the local folders account.

Archives are standard KMail ones, stored on another partition.

> As far as I recall I've seen reports about this duplicate emails issue
> since the 4.1x days meaning that the versions I'm still using aren't
> immune. Yet I've never seen any sign of it (that wasn't due to the way
> GMail imap folders work). I do sometimes have an issue where email seems
> to get lost and newly received email doesn't show up. Annoying, but I
> only have to quit Kontact, do `akonadictl fsck`, possibly an akonadi
> restart and things work again.

Yes, me too. Since the onset of plasma, though, they're considerably worse, 
and not just in number.

Today, for example, I've had two mailing-list replies also CC'd to me. In 
both cases the CC appeared in my inbox, as it should, but the list reply 
didn't appear anywhere. Your message was one of those; I had to move the CC 
into the list folder myself.

Then again, in the recent weeks of my latest struggle with it, I've had 
dozens of duplicates of messages suddenly appear in my inbox, even when I've 
only just started the program - and none of my accounts are set to fetch 
mail on startup, and I didn't see any network activity. The spurious copies 
were duplicates of messages that had already been filtered into other 
folders. I don't remember anything like that happening with KMail-1. [1]

As for "akonadi fsck," until this week, this has never done anything for me. 
The bash prompt returned immediately and I couldn't see any evidence that an 
fsck had been done. This week, though, I've tried it twice more, and each 
time it went away down a black hole. /bin/ps showed it, but /usr/bin/top 
didn't, and I never got my prompt back; again I couldn't see any trace of it 
doing or having done anything. It's useless here. The same applies to 
"akonadi vacuum."

I've lost count of the times I've deleted my user account, created another 
one from scratch and tried to restore my e-mails. My reason for doing that, 
of course, was to ensure that nothing weird could hang on from old failures, 
such as damaged e-mails. The latest time, though, was yesterday, when I 
didn't bother trying to restore my e-mails; just left the folders empty to 
start again. [2]

Sys-kernel/gentoo-sources-4.12.5, but 4.12.12 from today
KDE-plasma-5.10.4-r1, but 5.10.5 from today
kde-apps/kmail-17.04.3

Maybe I should try yet another "emerge -e world." It doesn't seem to have 
done any good before, though. I could try Luis Felipe's idea too. If I could 
find a satisfactory alternative to KMail, together with a practicable way to 
export and import, I would.

[1]	And that was with only a few messages in a new collection as in [2].

-- 
Regards,
Peter.