// Flow of inbound mails
//
// Convert to png with Graphviz:
//  dot -Tpng flow.inbound.dot -o flow.inbound.png
digraph inbound {
    label="Flow of Inbound Mail"

    sender[label="Sender"]
    sender_server[label="Sender Server"]
    //postfix[label="Postfix (MTA)", style=filled]
    postfix_postscreen[label="Postfix (postscreen)", style=filled]
    postfix_smtpd[label="Postfix (smtpd)", style=filled]
    //postfix_iredapd[label="Postfix (smtpd)"]
    dovecot[label="Dovecot (POP3/IMAP/Sieve/LDA/LMTP/SASL)", style=filled]
    iredapd[label="iRedAPD (Postfix Policy Server)", style=filled, shape=diamond]
    db[label="OpenLDAP, MySQL/MariaDB/PostgreSQL", style=filled]
    //amavisd[label="Amavisd", style=filled]
    amavisd_10024[label="Amavisd (port 10024)", style=filled, shape=diamond]
    postfix_queue_10025[label="Postfix queue", style=filled]
    sa_clamav[label="SpamAssassin, ClamAV", style=filled]
    mailboxes[label="Mailboxes"]

    // Flow of inbound emails
    sender -> sender_server[style=dotted]
    sender_server -> postfix_postscreen[label=" Enter iRedMail Server, Port 25", style=dotted]
    postfix_postscreen -> sender_server[label=" REJECT", color=red]
    postfix_postscreen -> postfix_smtpd
    postfix_smtpd -> iredapd[label=" Greylisting \nWhitelisting \nBlacklisting \nThrottling \n SRS (Recipient Address Rewriting, port 7779) \n..."]
    postfix_smtpd -> db[label="User verification"]
    iredapd -> postfix_smtpd[label=" DUNNO \nREJECT \n451 (Greylisting) \nOK (Whitelisting)...", color=blue]
    iredapd -> db[label="User verification"]
    postfix_smtpd -> sender_server[label=" REJECT \n451 (Greylisting)", color=red]
    postfix_smtpd -> amavisd_10024[label=" Spam/Virus scanning\nDKIM verification\nand more"]
    amavisd_10024 -> postfix_smtpd[label=" DISCARD\nREJECT\nBOUNCE...", color=blue]
    amavisd_10024 -> sa_clamav[label=" Spam/Virus Scanning \nDKIM verification \n...", dir="both"]
    amavisd_10024 -> db[label=" User verification \nWhite/Blacklisting \nQuarantine Spam/Virus \n..."]
    amavisd_10024 -> postfix_queue_10025[label="Re-inject scanned message to queue (Port 10025)"]
    postfix_queue_10025 -> dovecot[label=" Pipe/LMTP"]
    dovecot -> db[label=" User Authentication"]
    dovecot -> mailboxes[label=" LDA, LMTP"]
    dovecot -> postfix_smtpd[label=" REJECT (mailbox quota exceeded)", color=blue]
    //end_users -> dovecot[label="Retrieve mails via POP3/IMAP"]
    //end_users -> postfix[label="Send email (port 587)"]
    //Webmail -> dovecot[label="Access mailbox on web browser (IMAP)"]
    //Webmail -> postfix[label="Send email (port 587)"]
    iRedAdmin -> db[label="Account management \nand more"]
}