Mails becomes unread

I’m facing this problem when i come in the morning i found that all Emails become unread then i marked them read on next day when i open my mail database i found that all mails are unread

could any body tell me why is that happened

Subject: Mails becomes unread

Sounds like an agent is running overnight that makes changes in all documents…

Take care : if an agent uses the statement :

FIELD fieldname:=fieldname ;

Then in R6 the document is regarded as being changed (and thus unread), even when no changes were made. In R5, this was different. You may want to remove the 'FIELD fieldname:=fieldname ; '-lines in the agent code, because they’re no longer required in R6.

Subject: Mails becomes unread

but this problem happened to me only not all users