Bug 323536

Summary:	displaying mail, marking as read is slow
Product:	[Applications] kmail2	Reporter:	Roman K. <roman.karlstetter>
Component:	general	Assignee:	kdepim bugs <kdepim-bugs>
Status:	RESOLVED UNMAINTAINED
Severity:	normal	CC:	brix, keplicz, Martin, sven.burmeister
Priority:	NOR
Version:	4.11
Target Milestone:	---
Platform:	openSUSE
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Roman K. 2013-08-15 08:34:05 UTC

Since I updated to KDE SC 4.11, kmail is very slow displaying mails, it takes 5 minutes or more for a mail to be displayed. The same problem appears when marking it as read. While waiting for the mail to be displayed, kmail apparently does some work, as CPU usage is at around 20%.

I tried to remove all mail filters, I disabled nepomuk mail indexing, but the problem persists.
In akonadiconsole,  the mails display more or less instantly, so there seems to be a problem in kmail. 

Reproducible: Always

Steps to Reproduce:
1. Select mail in folder/Mark mail as read
2. Wait
Actual Results:  
Mail is displayed/marked as read after 5 minutes or so

Expected Results:  
Mail is displayed/marked as read instantly

Comment 1 Thomas Brix Larsen 2013-08-15 14:09:33 UTC

I have the same issue, but also kontact/kmail is slowly leaking memory until the OOM killer murders it.

This keeps repeating in akonadiconsole/debug:

kontact-964899043 (0x21feea0) 35640 LSUB 0 INF (MIMETYPE (message/rfc822)) () 
kontact-964899043 (0x21feea0) * 20 12 (NAME "Sendte e-mails" MIMETYPE (message/rfc822 inode/directory) REMOTEID "Sendte e-mails" REMOTEREVISION "1366838463000" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "sent-mail" ENTITYDISPLAY "(\"Sendte e-mails\" \"mail-folder-sent\" \"\" ())") 
kontact-964899043 (0x21feea0) * 24 12 (NAME "affald" MIMETYPE (message/rfc822 inode/directory) REMOTEID "affald" REMOTEREVISION "1371977639000" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "trash" ENTITYDISPLAY "(\"affald\" \"user-trash\" \"\" ())") 
kontact-964899043 (0x21feea0) * 13 12 (NAME "drafts" MIMETYPE (message/rfc822 inode/directory) REMOTEID "drafts" REMOTEREVISION "" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "drafts" ENTITYDISPLAY "(\"drafts\" \"document-properties\" \"\" ())") 
kontact-964899043 (0x21feea0) * 14 12 (NAME "inbox" MIMETYPE (message/rfc822 inode/directory) REMOTEID "inbox" REMOTEREVISION "" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "inbox" ENTITYDISPLAY "(\"inbox\" \"mail-folder-inbox\" \"\" ())") 
kontact-964899043 (0x21feea0) * 21 12 (NAME "indbakke" MIMETYPE (message/rfc822 inode/directory) REMOTEID "indbakke" REMOTEREVISION "" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "inbox" ENTITYDISPLAY "(\"indbakke\" \"mail-folder-inbox\" \"\" ())") 
kontact-964899043 (0x21feea0) * 22 12 (NAME "kladder" MIMETYPE (message/rfc822 inode/directory) REMOTEID "kladder" REMOTEREVISION "" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "drafts" ENTITYDISPLAY "(\"kladder\" \"document-properties\" \"\" ())") 
kontact-964899043 (0x21feea0) * 15 12 (NAME "outbox" MIMETYPE (message/rfc822 inode/directory) REMOTEID "outbox" REMOTEREVISION "" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "outbox" ENTITYDISPLAY "(\"outbox\" \"mail-folder-outbox\" \"\" ())") 
kontact-964899043 (0x21feea0) * 16 12 (NAME "sent-mail" MIMETYPE (message/rfc822 inode/directory) REMOTEID "sent-mail" REMOTEREVISION "1292353340000" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "sent-mail" ENTITYDISPLAY "(\"Sendte e-mails\" \"mail-folder-sent\" \"\" ())") 
kontact-964899043 (0x21feea0) * 23 12 (NAME "skabeloner" MIMETYPE (message/rfc822 inode/directory) REMOTEID "skabeloner" REMOTEREVISION "" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "templates" ENTITYDISPLAY "(\"skabeloner\" \"document-new\" \"\" ())") 
kontact-964899043 (0x21feea0) * 17 12 (NAME "templates" MIMETYPE (message/rfc822 inode/directory) REMOTEID "templates" REMOTEREVISION "" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "templates" ENTITYDISPLAY "(\"skabeloner\" \"document-new\" \"\" ())") 
kontact-964899043 (0x21feea0) * 18 12 (NAME "trash" MIMETYPE (message/rfc822 inode/directory) REMOTEID "trash" REMOTEREVISION "1309721092000" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "trash" ENTITYDISPLAY "(\"affald\" \"user-trash\" \"\" ())") 
kontact-964899043 (0x21feea0) * 19 12 (NAME "udbakke" MIMETYPE (message/rfc822 inode/directory) REMOTEID "udbakke" REMOTEREVISION "0" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "outbox" ENTITYDISPLAY "(\"udbakke\" \"mail-folder-outbox\" \"\" ())") 
kontact-964899043 (0x21feea0) * 12 0 (NAME "Local Folders" MIMETYPE (message/rfc822 inode/directory) REMOTEID "/home/brix/.local/share/local-mail" REMOTEREVISION "" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT false INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) AccessRights "wcdC" SpecialCollectionAttribute "local-mail" ENTITYDISPLAY "(\"Local Folders\" \"folder\" \"\" ())") 
kontact-964899043 (0x21feea0) * 62 59 (NAME "Drafts" MIMETYPE (message/rfc822 inode/directory) REMOTEID ".Drafts" REMOTEREVISION "" RESOURCE "akonadi_imap_resource_4" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL 5 CACHETIMEOUT 60 SYNCONDEMAND true LOCALPARTS (ENVELOPE HEAD)) uidnext "229" collectionflags "\\Answered \\Flagged \\Deleted \\Seen \\Draft \\*" uidvalidity "1303139372") 
kontact-964899043 (0x21feea0) * 61 59 (NAME "INBOX" MIMETYPE (message/rfc822 inode/directory) REMOTEID ".INBOX" REMOTEREVISION "" RESOURCE "akonadi_imap_resource_4" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL 5 CACHETIMEOUT 60 SYNCONDEMAND true LOCALPARTS (ENVELOPE HEAD)) ENTITYDISPLAY "(\"Indbakke\" \"mail-folder-inbox\" \"\" ())" uidnext "61353" collectionflags "\\Answered \\Flagged \\Deleted \\Seen \\Draft KMAILFORWARDED KMAILTODO KMAILWATCHED KMAILIGNORED $FORWARDED $TODO $WATCHED $IGNORED $ATTACHMENT $REPLIED $JUNK $MDNSent \\*" uidvalidity "1243311695") 
kontact-964899043 (0x21feea0) * 60 59 (NAME "Sent" MIMETYPE (message/rfc822 inode/directory) REMOTEID ".Sent" REMOTEREVISION "" RESOURCE "akonadi_imap_resource_4" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL 5 CACHETIMEOUT 60 SYNCONDEMAND true LOCALPARTS (ENVELOPE HEAD)) uidnext "158" collectionflags "\\Answered \\Flagged \\Deleted \\Seen \\Draft $REPLIED $Forwarded \\*" uidvalidity "1303139371") 
kontact-964899043 (0x21feea0) * 59 0 (NAME "brix-verden.dk" MIMETYPE (inode/directory) REMOTEID "imap://brix@brix-verden.dk/" REMOTEREVISION "" RESOURCE "akonadi_imap_resource_4" VIRTUAL 0 CACHEPOLICY (INHERIT false INTERVAL 5 CACHETIMEOUT 60 SYNCONDEMAND true LOCALPARTS (ENVELOPE HEAD)) noselect "1") 
kontact-964899043 (0x21feea0) 35640 OK List completed 
kontact-964899043 (0x21feea0) 35641 LSUB 0 INF (MIMETYPE (message/rfc822)) () 
kontact-964899043 (0x21feea0) * 20 12 (NAME "Sendte e-mails" MIMETYPE (message/rfc822 inode/directory) REMOTEID "Sendte e-mails" REMOTEREVISION "1366838463000" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "sent-mail" ENTITYDISPLAY "(\"Sendte e-mails\" \"mail-folder-sent\" \"\" ())") 
kontact-964899043 (0x21feea0) * 24 12 (NAME "affald" MIMETYPE (message/rfc822 inode/directory) REMOTEID "affald" REMOTEREVISION "1371977639000" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "trash" ENTITYDISPLAY "(\"affald\" \"user-trash\" \"\" ())") 
kontact-964899043 (0x21feea0) * 13 12 (NAME "drafts" MIMETYPE (message/rfc822 inode/directory) REMOTEID "drafts" REMOTEREVISION "" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "drafts" ENTITYDISPLAY "(\"drafts\" \"document-properties\" \"\" ())") 
kontact-964899043 (0x21feea0) * 14 12 (NAME "inbox" MIMETYPE (message/rfc822 inode/directory) REMOTEID "inbox" REMOTEREVISION "" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "inbox" ENTITYDISPLAY "(\"inbox\" \"mail-folder-inbox\" \"\" ())") 
kontact-964899043 (0x21feea0) * 21 12 (NAME "indbakke" MIMETYPE (message/rfc822 inode/directory) REMOTEID "indbakke" REMOTEREVISION "" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "inbox" ENTITYDISPLAY "(\"indbakke\" \"mail-folder-inbox\" \"\" ())") 
kontact-964899043 (0x21feea0) * 22 12 (NAME "kladder" MIMETYPE (message/rfc822 inode/directory) REMOTEID "kladder" REMOTEREVISION "" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "drafts" ENTITYDISPLAY "(\"kladder\" \"document-properties\" \"\" ())") 
kontact-964899043 (0x21feea0) * 15 12 (NAME "outbox" MIMETYPE (message/rfc822 inode/directory) REMOTEID "outbox" REMOTEREVISION "" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "outbox" ENTITYDISPLAY "(\"outbox\" \"mail-folder-outbox\" \"\" ())") 
kontact-964899043 (0x21feea0) * 16 12 (NAME "sent-mail" MIMETYPE (message/rfc822 inode/directory) REMOTEID "sent-mail" REMOTEREVISION "1292353340000" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "sent-mail" ENTITYDISPLAY "(\"Sendte e-mails\" \"mail-folder-sent\" \"\" ())") 
kontact-964899043 (0x21feea0) * 23 12 (NAME "skabeloner" MIMETYPE (message/rfc822 inode/directory) REMOTEID "skabeloner" REMOTEREVISION "" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "templates" ENTITYDISPLAY "(\"skabeloner\" \"document-new\" \"\" ())") 
kontact-964899043 (0x21feea0) * 17 12 (NAME "templates" MIMETYPE (message/rfc822 inode/directory) REMOTEID "templates" REMOTEREVISION "" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "templates" ENTITYDISPLAY "(\"skabeloner\" \"document-new\" \"\" ())") 
kontact-964899043 (0x21feea0) * 18 12 (NAME "trash" MIMETYPE (message/rfc822 inode/directory) REMOTEID "trash" REMOTEREVISION "1309721092000" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "trash" ENTITYDISPLAY "(\"affald\" \"user-trash\" \"\" ())") 
kontact-964899043 (0x21feea0) * 19 12 (NAME "udbakke" MIMETYPE (message/rfc822 inode/directory) REMOTEID "udbakke" REMOTEREVISION "0" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) SpecialCollectionAttribute "outbox" ENTITYDISPLAY "(\"udbakke\" \"mail-folder-outbox\" \"\" ())") 
kontact-964899043 (0x21feea0) * 12 0 (NAME "Local Folders" MIMETYPE (message/rfc822 inode/directory) REMOTEID "/home/brix/.local/share/local-mail" REMOTEREVISION "" RESOURCE "akonadi_maildir_resource_5" VIRTUAL 0 CACHEPOLICY (INHERIT false INTERVAL -1 CACHETIMEOUT 1 SYNCONDEMAND true LOCALPARTS (ENVELOPE)) AccessRights "wcdC" SpecialCollectionAttribute "local-mail" ENTITYDISPLAY "(\"Local Folders\" \"folder\" \"\" ())") 
kontact-964899043 (0x21feea0) * 62 59 (NAME "Drafts" MIMETYPE (message/rfc822 inode/directory) REMOTEID ".Drafts" REMOTEREVISION "" RESOURCE "akonadi_imap_resource_4" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL 5 CACHETIMEOUT 60 SYNCONDEMAND true LOCALPARTS (ENVELOPE HEAD)) uidnext "229" collectionflags "\\Answered \\Flagged \\Deleted \\Seen \\Draft \\*" uidvalidity "1303139372") 
kontact-964899043 (0x21feea0) * 61 59 (NAME "INBOX" MIMETYPE (message/rfc822 inode/directory) REMOTEID ".INBOX" REMOTEREVISION "" RESOURCE "akonadi_imap_resource_4" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL 5 CACHETIMEOUT 60 SYNCONDEMAND true LOCALPARTS (ENVELOPE HEAD)) ENTITYDISPLAY "(\"Indbakke\" \"mail-folder-inbox\" \"\" ())" uidnext "61353" collectionflags "\\Answered \\Flagged \\Deleted \\Seen \\Draft KMAILFORWARDED KMAILTODO KMAILWATCHED KMAILIGNORED $FORWARDED $TODO $WATCHED $IGNORED $ATTACHMENT $REPLIED $JUNK $MDNSent \\*" uidvalidity "1243311695") 
kontact-964899043 (0x21feea0) * 60 59 (NAME "Sent" MIMETYPE (message/rfc822 inode/directory) REMOTEID ".Sent" REMOTEREVISION "" RESOURCE "akonadi_imap_resource_4" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL 5 CACHETIMEOUT 60 SYNCONDEMAND true LOCALPARTS (ENVELOPE HEAD)) uidnext "158" collectionflags "\\Answered \\Flagged \\Deleted \\Seen \\Draft $REPLIED $Forwarded \\*" uidvalidity "1303139371") 
kontact-964899043 (0x21feea0) * 59 0 (NAME "brix-verden.dk" MIMETYPE (inode/directory) REMOTEID "imap://brix@brix-verden.dk/" REMOTEREVISION "" RESOURCE "akonadi_imap_resource_4" VIRTUAL 0 CACHEPOLICY (INHERIT false INTERVAL 5 CACHETIMEOUT 60 SYNCONDEMAND true LOCALPARTS (ENVELOPE HEAD)) noselect "1") 
kontact-964899043 (0x21feea0) 35641 OK List completed

Comment 2 Piotr Keplicz 2013-08-15 20:31:58 UTC

There's a similar problem on Ubuntu with the latest 4.11 packages - it takes ages to display a message or process it in any way. Kontact, akonadiserver and mysqld processes utilize up to 100% of CPU.

Debugger in akonadiconsole is being flooded with messages similar to the one below, looping for all the folders:

kontact-1223398355 (0xa07ba78) * 224 51 (NAME "INBOX" MIMETYPE (message/rfc822 inode/directory) REMOTEID "/INBOX" REMOTEREVISION "" RESOURCE "akonadi_imap_resource_3" VIRTUAL 0 CACHEPOLICY (INHERIT true INTERVAL 60 CACHETIMEOUT -1 SYNCONDEMAND true LOCALPARTS (ENVELOPE HEAD RFC822)) ENTITYDISPLAY "(\"Skrzynka odbiorcza\" \"mail-folder-inbox\" \"\" ())" uidnext "93137" collectionflags "\\Answered \\Flagged \\Draft \\Deleted \\Seen $MDNSent Junk NonJunk $Forwarded $Label4 $Label1 $Label2 $Label3 $Label5 NotJunk JunkRecorded KMAILFORWARDED KMAILTODO KMAILWATCHED KMAILIGNORED $TODO $WATCHED $IGNORED receipt-handled $has_cal $ATTACHMENT $REPLIED $JUNK $SIGNED $NOTJUNK \\*" uidvalidity "1087477203" collectionquota "65810432 307200000" imapacl "cyrus lrswipcda % XXXXXXXXXXX lrswipcda %% " collectionannotations "/vendor/cmu/cyrus-imapd/condstore false % /vendor/cmu/cyrus-imapd/duplicatedeliver false % /vendor/cmu/cyrus-imapd/lastpop 18-Mar-2011 09:50:14 +0100 % /vendor/cmu/cyrus-imapd/partition default % /vendor/cmu/cyrus-imapd/pop3newuidl true % /vendor/cmu/cyrus-imapd/sharedseen false % /vendor/cmu/cyrus-imapd/size 54435965 % /vendor/kolab/folder-test true" imapquota "user/XXXXXXXXXXXXX %%%% STORAGE % 300000 %%%% STORAGE % 64268" AccessRights "wcdCD" timestamp "1376597391")

Comment 3 Piotr Keplicz 2013-08-16 21:00:36 UTC

It seems that removing some broken maildir resources and recreating akonadi db fixed the problem here.

Comment 4 Roman K. 2013-08-17 15:40:07 UTC

Yeah, removing and readding the local maildir resource fixes the problem for me, too. Thanks for the hint.

Comment 5 Roman K. 2013-08-18 08:28:46 UTC

The problem reappeared again. I selected a completely empty folder for the maildir resource, kmail is much more responsive now.

Comment 6 Martin Steigerwald 2015-09-10 10:52:35 UTC

Thank you Roman for your report and Thomas for your comment. Sorry for taking long time to reply.  If you still see performance issues please open new reports. But please follow the
following guide lines to avoid unnecessary work for the developers:

- Ideally test with KDEPIM and Akonadi 15.08. It contains some performance
improvements like the binary protocol.

- Otherwise at least use KDEPIM 4.14.10 and newest Akonadi 1.13 you can get as
it already contains some performance improvements.

- If you can wait, please retest with KDEPIM and Akonadi 15.12 once they become
available for you. Akonadi 15.12 will contain *massive* performance
improvements implemented by Dan due to new database indexes, optimized queries
and leveled file_db directory. All of these are in master already, so if you
dare use kdesrc-build to compile KF5, kdepim and kdepim-runtime. I am using
this currently and it basically moves the bottleneck to KMail (slow threading
for example). It is a *huge* improvement. Also Volker and others work on
performance improvements in KMail as well.

Thank you and greetings from KDE Randa Meetings,
Martin