One of our iPhone users once in a while gets this response in e-mail from our mobility server since we updated it to Mobility 2.0.1.
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From: Mobility Administrator
Date: 18 Jun 2014 22:56:26 GMT+2
To: "Username" <username@domain.nl>
Subject: Failed to Add Item

Mobility failed to add the following item because: Generic file I/O error

Item Type: Email
Subject: Re: Project blabla
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From: Mobility Administrator
Date: 17 Jul 2014 23:00:48 GMT+2
To: "Username"
Subject: Failed to Add Item

Mobility failed to add the following item because: Generic file I/O error

Item Type: Email
This one came two times with only 3mins between. Was a response to separate e-mails.
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Strange symptom: The message is saved, sent and delivered anyways.
Occurrence: maybe once every 4 weeks.
Sent to both internal as external addresses.
Plenty of free space on both the Mobility and GWIA server.
Update order: Data Synchronizer 1.2.5 to 2.0.0 (CD update) and then through yast-patterns to 2.0.1 everything according to the upgrade manual.
Update date: 26/may/2014
All hard disks in SAN are fine, running on VM SLES11SP2

Any ideas what might be causing this?