Mail.app connection errors (offline) after sleep My 10.8.2 MacBook Air is having constant connection errors in Mail.app when the computer has been sent to sleep or hibernate.

A small alert triangle appears next to all account names (I have several) in the sidebar. Mail reception only resumes after quitting and relaunching Mail.app.

I have verified that the net connection is up, and that connections settings and credentials are okay. Similar problems described here.
This might seem weird and unlikely, but these steps (originally written to restore broken Dictation) fixed it for me:


Go to ~/Library/Preferences
( &#x21E7;+&#x2318;+G )
Locate com.apple.assistant.plist and move it to the Trash
Open Dictation &amp; Speech preference panel, disable dictation
Reboot
Re-enable Dictation &amp; Speech.


Any hints on why this is working are very welcome!