send email to registration of a Service Call but reply back error

[blackbabe]

I send an email to the smtp server, but then often get a reply back from service desk saying(sometime right and sometime wrong):

The E-mail you sent has not resulted in the registration or update of a Service
Call.
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The following error(s) occurred:
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For service call the following fields are required:

service.
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If you have any questions pertaining to this message, you can contact the helpdesk during normal support hours.
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This message has been generated automatically.
Please do not reply to this message.


and usually some of them have disapeared after restarting the SD service.

can you help me?