Mail Server

General

See https://help.ubuntu.com/community/MailServer for an introduction to MTA/Spamassassin

Briefly, the workflow for mail delivery is:

[Internet] -> postfix (MTA) -> procmail (MDA) -> SpamAssassin -> $HOME/Maildir

and for mail viewing:

$HOME/Maildir -> Courier (IMAP MUA) -> Thunderbird/Outlook

or

$HOME/Maildir -> Mutt/Pine

Postfix

Emptying deferred queue

To attempt redelivery:

sudo postfix flush

To simply delete all deferred mails:

sudo postsuper -d ALL

SpamAssassin

Pyzor

Meaning of output like:

82.94.255.100:24441     (200, 'OK')     1206    0

82.94.255.100

24441

Pyzor server

(200, 'OK')

HTTP response from server

1206

Number of spam matches for tested message

0

Number of whitelist (definite non-spam) matches for tested message

Pyzor will return 0 (identifying the message as spam) only if number of spam matches > 0 and number of whitelist matches = 0.