iOS devices, including iPhone, iPad and iPod touch may exhibit an issue in which the Mail app displays the message “Cannot Get Mail – The Connection to the Server Failed” when attempting to retrieve new messages, especially from Microsoft Exchange servers.
Fixes
Move all items from inbox to a different folder. The most commonly successful fix for this issue is to move all items from the inbox into a temporary folder created on the server. It appears that problematic messages in the inbox can cause the error message.
Upgrade Exchange Server. You may need to apply a service pack to the Exchange server to which your iPhone is connecting. Some users have reported that they need to install Exchange Server 2003 Service Pack 2 to eliminate this error.
Change Exchange security settings. Some users have reported that they needed to turn on “Include inheritable permissions from this object’s parent” in the user’s security options in Active Directory.
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AppleID:( on 
September 2, 2010 at 1:58 PM
For me it was an issue with the exchange-oma folder in IIS… see http://support.microsoft.com/?kbid=817379
October 29, 2010 at 5:52 PM
This a BUG on iPad, because if you delete all the accounts and you create a different one, all the old SMTP data and connections are still there
Shame on you Apple
June 21, 2011 at 11:50 AM
Thank you for this post! The “inheritable permissions” worked like a charm.
November 18, 2011 at 11:16 AM
Moving data to a temp folder cleared up the issue.
December 2, 2011 at 8:59 AM
These “Cannot Get Mail” messages can also appearing when the limit or concurrent connections from an IP is reached. Do you know what the server “concurrent IP connections” limit is set at? The standard is 4 and may need to be increased by your administrator.
February 10, 2012 at 10:19 AM
Thank you so much! This was driving me crazy. I found this article, sent “Include inheritable permissions from this object’s parent” in the user’s security options in Active Directory” to my Exchange Engineer and it worked. Thanks! DsC
February 27, 2012 at 8:31 PM
Very Simple .. just Change your password for your account on Exchange .
Cheers
April 4, 2012 at 11:22 AM
the “Include inheritable permissions from this object’s parent” worked perfectly for me on our Exchange 2010 server and my CEO’s iPad2
Thanks!
April 27, 2012 at 4:29 AM
Hi, this worked like a charm when moving the emails to a new created folder.
thanks
curt