When I wake my computer up from sleep all the Mail and Calendar accounts are offline?

Thanks Coffeenow NZ - Seemed to help me too.

My problem only started when 10.8.1 was applied.

Thanks. This has certainly helped email come back online itself (even though when it first awakes it shows the exclamation marks against each account, but then changes). This also happened after I installed ML.

Thanks for the tip!

worked for me, thanks coffeenow! 😀

Coffeenow NZ - Thanks a lot! Seems to be working brilliantly now!

I had precisely the same problem (MacBook Pro 13 inch, 2.7GHz i7 8GB on a WiFi network) after upgrading from Lion to Mountain Lion and tried all the usual things (PRAM reset, rebooting everything, deleting Library preferences etc) and potential fixes mentioned in this thread, but to no avail (except that -oddly- playing with the dictation as described by Coffeenow NZ did seem to work for a short period). So, I was for quite some time stuck with having to turn my WiFi off, Quit (or force quit) Mail, turn WiFi back on and start Mail again. Problem was replicated after clean install of Mountain Lion. No problems with an identical MacBook Pro on the same network running Lion.

So, it seemed that a network issue was the root cause (although, it must be said, I never had this problem with 10.7 Lion). I was running a Time Capsue/Airport network but in bridged mode to an aDSL router - provided preconfigured by our aDSL provider (iiNet- Australian) and which managed PPPoE/password authentication.

The eventual solution was to switch the aDLS router to Bridge mode, and use the Time Capsule to manage the whole network including PPPoE/password authentication and routing ---> has worked perfectly ever since. Moral of story for simpletons such as myself - Apple gear works best with Apple gear!

Unfortunately, this hasn't totally resolved the issue for me. The accounts still go offline and stay that way when I awaken it from sleep. At least they now reactivate themsleves after approximately 30 seconds.

I had the same problem again after updating to 10.8.2 (and Dictation stopped again)

The fix was as before but I only had to complete steps 1 & 2:

1) Locate and delete the file: ~/Library/Preferences/com.apple.assistant.plist

You can access the user Library folder if you click on Finder's CD menu on top left and then press & hold ALT (option) key on the keyboard. Library will appear and you can select it. Then you open Preferences and you find com.apple.assistant.plist file and move it to the trash.

2) Reboot Mac

Anyone else find this?

This hasn't worked for me. I never had dictation turned on, so I tried it but to no avail. I have done the os update and still no change, it's so frustrating

ahhh me too!

I tried.

First time I tried Sleep for a few minutes. Worked OK.

However, when I did Sleep for about 6 minutes, same old problem.

Thanks for trying.

I have the same problem on a 15" Retina MacBook Pro.

I've had this problem since I got it (running Lion) and still have it now running 10.8.4.

I still haven't found a fix for it.

I've never run dictation, so I didn't have a plist to delete. I've deleted all accounts and mail preferences, run all of Onyx's maintenance options, reset all network settings, all to no avail.

I have this problem after migrating to a MacBook Pro and updating to Mountain Lion.Using latest version of Mail (6.05). I don't have dictation turned on - so I don't have an apple.com.assistant.plist file to delete. Anyone else found another solution? Nothing has changed in my various Mail account settings.

In the "Detail" revealed in the Connection Doctor window of Mail - all of the accounts show the message "INITIATING CONNECTION" - but there is no response or follow up - they just stall at this point. If I "Check Again" the same set of INITIATING CONNECTION messages scroll up.

This may not be the most suitable solution for everyone - but I lived with this problem ever since Mountain Lion was released and it was infuriating having all my mail offline whenever I left the macbook for 5 minutes. I got used to just hitting ⌘+Q every time I resumed and just relaunched mail. This Macbook had only ever been 'updated' from Snow Leopard > Lion > Mountain Lion.

Anyway, two weeks ago I swapped out my (2010) Macbook Pro HDD for an SSD and performed a complete clean install of ML. This completely solved the problem for me (as well as a few others), I never use dictation so I have no idea about that, but mail never just goes offline anymore. With Time Machine getting important files back is so easy that I wouldn't hesitate to do a clean install again.

I say clean install, the only part I restored from the time machine backup during the install process was the system settings, such that it knew my time machine drive so it just carried on backing up where it left off. Once the system was running I just restored files as I wished.

The only thing that seems to work for me (and I've tried EVERYTHING) proposed on the forums is to set my iMac to never sleep in Energy Saver. Contemplating a clean install of Mavericks to see if that will make a difference.

Just an update to my situation:

I suspect my ISP's DNS servers are contributing to this problem. I found that if I switched my DNS to OpenDNS I never had the mail problem. (I used DNSCrypt to do this on the fly). I'm sure you could try any alternative DNS settings.

The "dictation fix" would work for a while but then something (a software update?) would stop it working and I'd have to fix it again. Changing DNS servers would fix it regardless.

I recently moved house and use a different ISP. No problems so far and I don't have to use an alternate DNS.