This page details how to view e-mail headers with the aim of noting the spam score assigned by SpamAssassin. This will assist in deciding what value to assign to the Spam Deletion Level in your individual SpamAssassin settings if you choose to use it with other than the recommended value of 20.

The line you're looking for should be towards the bottom of the header lines & starts: X-Spam-Status: Yes, hits=11.3 required=8.0 (or similar).

required=8.0 is set by the Spam Marking Level, in this case 8.
Note: Due to the complexity in handling e-mails with multiple recipients (CC: and BCC: included) the spam headers are handled differently. If it scores above your Spam Marking Level then required=0 will appear. If it scores below then no spam headers will appear at all. Your individual setting is still being applied.

hits=11.3 is generated by SpamAssassin & indicates the total points it allocated in assessing various aspects of the e-mail. The higher the number the more likely the e-mail is spam.

Yes indicates SpamAssassin assessed the e-mail as spam - hits exceeded required. Otherwise SpamAssassin indicates No.

The hits is the number you're after as it indicates the "spaminess" of the message. SpamAssassin works by assigning points to various aspects of an e-mail (both positive & negative) - the total indicates the probability of the e-mail being spam. A large positive score indicates high probability of spam & conversely a large negative score indicates a low probability of spam.

If you wish to use the Spam Deletion Level setting for SpamAssassin to automatically & irretrievably delete e-mail detected as spam from the mail server it would be wise to examine your e-mail headers & note the hits scores, particularly of false positives (real mail assessed as spam) as you don't wish to delete these.

Newsletters & similar bulk e-mail will often be marked as spam & may achieve a high score so ensure you whitelist these senders or they may be deleted along with the intended spam.

If you choose to set the Spam Deletion Level there is always a risk of deleting false positives so use it with caution. The recommended value of 20 will delete many spam messages, with a low risk of catching a false positive. With care you can lower it but this of course increases the risk of deleting real e-mail you want. The choice is yours - once the mail is deleted it's gone & can not be recovered.

View a message by double clicking it in the mailbox listing.

If the X-Spam-Status line is not displayed click on the Blah-Blah-Blah icon (above the message text) to display more headers.

Message > Show All Header Fields

Repeat to return to normal view.

View > Headers > All

Repeat to return to normal view.

Or select an e-mail then View > Message Source.

Select an e-mail. Click Display all headers (on right end of message header bar).

Select an e-mail.

File > Properties > Details > Internet

Or open an e-mail & select the Options tab.

Select an e-mail.

File > Properties > Details. Optionally click Message Source to view in new window.

Double click on desired e-mail. Click Raw view tab.

Message > Message view options > Show all message headers

Repeat to return to normal view.