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In general, no. While SpamAssassin is very good at picking out a large proportion of spam, it's impossible for a computer to do this job perfectly. You should only delete mail if you (and your users/customers) would find it acceptable to lose mail that might be legitimate. A much better idea is to filter possible spam into a separate folder that can be checked less frequently than the normal mailbox. It is possible to reject the mail at the smtp level, generating a delivery error, so the sender is notified that their message is rejected. This works well imo. You need to use a mail server that supports this(I use mimedefang+sendmail). Mimedefang also allows me to save the mail to a central archive that I can extract from if I get a FP. If you do reject mail at the 5xx delivery level you need to set your spam threshold higher then the default of 5.
But I really really want to do it anyway!
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