First of all, this is probably related to, but not the same as the following bugs:
289726, 290882, 293024, 296033.

I have set up some 20 email accounts, most of them are IMAP accounts, but there are also a few POP3 accounts. Initially I've set different time intervals for fetching email from all of them, although I learned just a few minutes ago, that this might not make a lot of sense for IMAP. 

Problem 1: Annoying notifications
Anyway, the problem  no. 1 is, that I quite often get very annoying notifications "Connection to server lost". These notifications don't come in one at a time, but are bombed at me all at once, some of them multiple times within less than a second. (Typically, they seem to appear either once or three time per lost connection).
One situation when this happens is when my provider cuts the connections once every 24 hours. The message as such is correct, then, but I would like to get rid of the very annoying sound, at least. However, I haven't found a settings option that would allow me to do this, without switching off KDE PIM notifications altogether.

Problem  2: KWallet
The second problem is that Akonadi resources are de-activated for lost connections. When the time is there to fetch mail, I have to re-issue my password for KWallet. Unfortunately, this is not only necessary once, but KWallet is opened for each account again, individualll, so I have to enter the very same passphrase 20 times, in the worst case. With KMail 1 KWallet was only called once, which is in fact how it *shoud* work.

Please note, that none of my accounts is Google. So the suspected cause of problems as described in some other bugs, is not limited to Google mail accounts. But as some others say, the problem occurs only after KMail2 has been running for while. Right after starting it, there's usually no problem.



Reproducible: Sometimes

Steps to Reproduce:
1. Create  multiple email accounts, IMAP and POP3, preferrably at multlple mail providers.
2. Set intervals for fetching email from all of them (including the IMAP accounts!).
3. Re-start KMail2, or maybe better your whole KDE session
4. Have KMail2 running for a while (up to 25 hours at a maximum may be necessary)
5. Look what happens to some or all of the relevant Akonadi resources, when your ISP cuts connections (most providers to that). Depending on your ISP and hardware (DSL modem, router...), you may be able to configure the time to fall into an hour of your choice.

This should give you a good chance to reproduce the problem for one specific situation (ISP cuts connection). However, there seem to other situations, when the issue comes up, but they are hard to reproduce.
Actual Results:  
see description

Expected Results:  
1. Behaviour should be like with KMail 1: Notification is there, when connection is lost, but much more discrete.
2. Lost connections should be re-established automatically in the background. 
3. KWallet should not bother the user with password requests. If nececessar, at all, ther should only be one request to enter the KWallet passphrase, not one per account.