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Lotus Domino 6 for Linux (SMTP) Server
Domino SMTP Server listens for
connection requests on port 25
Figure 3-3 Communication sequence for incoming SMTP mail
The general communication sequence of incoming SMTP mail is as follows:
1. Originating SMTP server makes a connection request to Domino SMTP
server on the TCP/IP port.
2. Domino SMTP server responds to the connection request and allows or
denies connection based on SMTP Inbound Controls on Server Configuration
document.
3. Originating SMTP server sends the MAIL FROM containing the sender's
internet address.
4. Domino SMTP Listener checks Inbound Sender Controls, comparing contents
of the MAIL FROM. If the maximum message size is enabled on the server
and the client has provided the message size as a parameter on the mail from
command, the inbound file size restrictions are performed (messages that are
too large are rejected).
5. Originating SMTP server sends the RCPT TO containing the internet address
of the intended recipient. (Note: Steps 5 and 6 are repeated for additional
recipients.)
6. Domino SMTP Listener checks Inbound Intended Recipients Controls,
comparing contents of the RCPT TO. If intended recipient is not a local user, it
checks Inbound Relay Enforcement and Inbound Relay Controls, comparing
contents to the RCPT TO.
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Lotus Domino 6 spam Survival Guide for IBM eServer
SMTP Configuration Checking Sequence
STEP 2
STEP 4
STEP 6
STEP 8
STEP 10
STEP 12
Firewall
STEP 1
STEP 3
STEP 5
STEP 7
STEP 9
STEP 11
SMTP Client/Server requests inbound connection
into Domino SMTP Server on port 25
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