Internal relayed messages captured due to Invalid Recipient

Problem

Emails being relayed through a Domino server where SpamSentinel is installed get blocked as Spam with the reason 'Invalid Recipient' because the recipient name is not in the Domino Directory.

Background Information

By default, SpamSentinel will scan all messages being received via SMTP into the Domino server whether they are destined for a local mailbox or being relayed out to the Internet.  This also applies to messages being send through Domino by users who are managing their mail with a POP or IMAP client.

Solutions

1.  Ignore Not Found Recipients

In the SpamSentinel Server Configuration document go to the 'Advanced' tab then the 'Recipient Procesing' sub-tab and change the setting 'Invalid Recipient Processing' to 'Ignore not found recipients' which is the default value.  This will prevent SpamSentinel from stopping a message just because the user isn't found in the Domino Directory.

2.  Allow Relaying from Specific IP Address(es)

If SMTP messages that need to be relayed to the Internet are only coming from trusted IP addresses, you can instruct SpamSentinel to skip scanning messages arriving from those locations.

a.  In the SpamSentinel Server Configuration document, go to the 'White & Black Lists' tab then the 'White Lists' sub tab and scroll down to the section 'Do Not Check These Messages'

b.  Select the option 'SMTP Relay Hosts' for the field 'IP Addresses'.  This will cause further fields to appear.

c.  Enter the IP address of the originating mail server(s) into the 'Addresses to Allow Relay' field.

d.  Select the option 'Only check last received' for the field 'Only check last received field' then save the document