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Whitelist a server in Symantec SMS 4.6?

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All Forums >> [Microsoft Exchange 2000] >> Server Security >> Whitelist a server in Symantec SMS 4.6? Page: [1]
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Whitelist a server in Symantec SMS 4.6? - 27.Jun.2006 3:56:30 PM   


Posts: 1
Joined: 10.Jan.2002
Status: offline
Hello all,

I am running Exchange 2000 with Symantec Mail Security 4.6. We have contacted with a commercial service to provide us a secondary email server offsite. The offsite server collects and queues mail for us whenever our system is unreachable to the outside world.

We are having some issues with the queue hanging when the secondary server tries to transfer mail to us. I would like to "whitelist" the server to bypass filtering as an aid in trouble shooting the problem but I can't find a way to do that in the SMS software. I see how to whitelist by sender name but I can't find any way to white list a particular server.

Can anyone help with this issue?

Dave J
Post #: 1
RE: Whitelist a server in Symantec SMS 4.6? - 3.Feb.2010 5:18:55 AM   


Posts: 1
Joined: 3.Feb.2010
Status: offline
You seem to be combining concepts of a sender whitelist (allowed
sender users/domains) and a recipient whitelist (allowed recipient

Out-of-the-box, IIS SMTP supports a form of recipient whitelist, since
you can configure it to only accept mail sent in _unauthenticated_
sessions for its local and alias domains and a specific list of relay
remote domains. All other remote domains will not be serviced in
unauthenticated sessions. You can also choose whether authenticated
sessions will be allowed higher privileges so that they may send to
unlisted remote domains.

With 5xxSink, the recipient whitelist is enhanced greatly by only
accepting mail to a list of specific _users_ @ serviced domains --
instead of initially accepting mail to any username @ local, alias,
and remote domains *regardless* of whether a mailbox exists.

As far as a sender whitelist, 5xxSink has no participation at that
level (the MAIL FROM part of the SMTP convo).

IIS SMTP on its own can restrict connections at the stack level by
source IP (so no one else can even start a convo with the server); it
can restrict delivery to both local/listed and unlisted domains by
always requiring an authenticated session; or it can allow anonymous
sessions to deliver to local/listed domains, while requiring an auth'd
session to send to unlisted domains.

If you only want to accept mail from specific partner domains, it is
best to require incoming authentication for all mail and not even
publish an MX record. Otherwise, you're just inviting people to forge
one of your allowed sender domains, easily foregoing any apparent
security; further, publishing an MX in the public DNS for a server
that, in reality, accepts mail only from a private list of allowed
servers is misleading.

If you did not want to require a login and password -- by the way, you
*can* log in to IIS SMTP regardless of whether you have a local
mailbox; you just need to exist in the SAM or AD -- but you want to
have non-forgeable protection, you'd gather the source IPs of the
outbound mailservers of your allowed domains and allow anonymous
connections only from those IPs. Problem with this approach is
maintenance; logins and passwords are portable once you provide them
to a partner, while their source IP would have to be changed on your
end if it ever changes on theirs.
I hope these could get you a reply.

(in reply to davelj)
Post #: 2

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