Very Computer

Sorry about the large cross-posting, but I didn't want to miss getting my
questions out to any helpful souls out there.  My boss tossed out a copy of
linux to me and asked me to make a secondary mail spooler for our
NT/Exchange 5.5 environment (for free, of course - I can't spend no $$$$).
Something that will accept SMTP mail (IF our primary SMTP mail server is
down) , and just spool it to our bridgehead server.  And if it cannot send
it over, it will keep retrying until it can send the queue on over.

Questions:

1) What product running under Redhat Linux would be good for this?
2) Do you know of any how-to docs available for the product that you
recommend?
3) Do you know of any how-to docs that discuss this specific situation?
4) do you have any other suggestions?

Thanx for all your help.  If you could take the time to email me, it would
be awsome!  If you live in the LA, CA area, and can help, I will buy you
some beers!

Chris

That's what every SMPT server will do. Unless you have some reason to
believe the Exchange server will be down for days there's probably no
reason to have a secondary MX.

Quote:>Questions:

>1) What product running under Redhat Linux would be good for this?

Sendmail.

Quote:>2) Do you know of any how-to docs available for the product that you
>recommend?

Get the "Bat Book" from O'Reilly & Associates. The first couple of
sections will probably be all you need to read to get things working.

------------------
Rich Matheisen
MCSE+I, Exchange MVP
MS Exchange FAQ at http://www.swinc.com/resource/exch_faq.htm

I respectfully disagree. We have an external ISP host a secondary MX server
that simply collects all email in the event of an outage, then forwards it
to our main in-house server when it returns to service.

Several reasons for this suggestion
1. T1's go down
2. Servers go down
3. Major virus attacks. When the luv letter [misspelled to prevent filtering
of msg] virus hit so hard and before the antivirus, we simply disconnected
our email server from the external network. We let the host for the
secondary MX worry about cleaning their server, and in the meantime, there
wasn't any propogation of the virus. The next morning, we reconnected our
email server and had a ZERO incidence of infection. Email was delayed by
approx 24hrs and antivirus software had caught up by then. Sure beats the
alternative!
4. When you host your own email for your domain, any unavailability bounces
email back to the sender. This can be very costly from a business point of
view. Sure, it'll *probably* try to resend, but sometimes it's too late, and
some servers only send every 24hrs. It also gives a poor impression and/or
lost sales if you do business on the internet.

Hope this helps.
John

Feel free to disagree all you like. Just don't expect me to agree with
your POV.

Quote:>We have an external ISP host a secondary MX server
>that simply collects all email in the event of an outage, then forwards it
>to our main in-house server when it returns to service.

>Several reasons for this suggestion
>1. T1's go down

And mail will be resent by the originating server when it's back in
service.

Quote:>2. Servers go down

Stand up another server and adjust the MX record.

Quote:>3. Major virus attacks. When the luv letter [misspelled to prevent filtering
>of msg] virus hit so hard and before the antivirus, we simply disconnected
>our email server from the external network. We let the host for the
>secondary MX worry about cleaning their server, and in the meantime, there
>wasn't any propogation of the virus.

And if the secondary MX just queued the mail and sent it to you, still
infected, afterward?

Quote:>The next morning, we reconnected our
>email server and had a ZERO incidence of infection. Email was delayed by
>approx 24hrs and antivirus software had caught up by then. Sure beats the
>alternative!

You're just the type of company I'd like to avoid. Let someone else do
all the heavy lifting -- great. No sense in investing in your own AV
software, eh?

Quote:>4. When you host your own email for your domain, any unavailability bounces
>email back to the sender. This can be very costly from a business point of
>view. Sure, it'll *probably* try to resend, but sometimes it's too late, and
>some servers only send every 24hrs. It also gives a poor impression and/or
>lost sales if you do business on the internet.

No mail is "bounced" if your server is unavailable, unless it's
unavailable for a /very/ long time. How the mail being queued (and
unanswered, which, BTW, also gives you a bad reputation) can hurt
business is speculative, don't you think?

------------------
Rich Matheisen
MCSE+I, Exchange MVP
MS Exchange FAQ at http://www.swinc.com/resource/exch_faq.htm

No problem. The diversity of solutions is what makes newsgroups invaluable.
A solution for a small company like ours may not work for a larger company.
Here's why this solution worked for us.

If the T1 goes down, sometimes it could take hours to a day to bring it back
up, depending on the cause. We are not staffed 24/7, so an outage over the
weekend spells trouble for us.

If we reported it Mon am, it is possible that our mailserver has been
unavailable for several days (Fri eve- Mon afternoon, assuming a quick fix
to the T1 problem). A second server wouldn't help in this situation.

Our AV solution wouldn't have helped with the luv virus. It took several
hours for Symantec to release a definition, and a good portion of our
customer base (gov't) was spewing propagation messages wildly.

Our ISP is very helpful and provides a number of addon services to
compliment our own. They are happy to do it, and less overhead for us. For
example, we host our website with the ISP instead of internally. No DMZ
issues, no outage headaches, and most importantly, reduced cost. The cost of
a high bandwidth connection to support a website and all your corporate
traffic vs the cost of having a high bandwidth ISP host your site, and not
worrying about the Sat am calls because the mission critical website is down
is heavily weighted towards using the service of the ISP.

I started and operated an ISP years ago. I sold it when the market was hot.
The early am and weekend troubleshooting gets old really fast :-)

Bounced email happens. It depends upon the resend settings on the sending
server, and the weekend scenario I mentioned could definitely exceed the
typical 48hr threshold.

You are correct in saying that unanswered emails can cause a similar poor
impression. It's sort of like calling a business' telephone number and not
getting an answer. That's bad. But it's worse to call and hear, "...number's
been disconnected..."  Lesser of two evils, I guess.

People like you with lots of knowledge and probably lots of resources can
setup redundant solutions and creative configurations, and that's great. It
probably works better. But I get the impression from reading many of the
postings that there are a lot of people here who don't have you degree of
knowledge and are looking for easy, cheap solutions. Call your ISP and in
about 5 minutes you're finished. They'll most likely have it up within a
day. Doesn't get much easier :-)

Our ISP charges $25/month for the backup MX. In my book that's a nobrainer.
Saves cost of server, hassle of outages, etc, etc.

Basically, if you've got the extra server and resources, build a better
solution. Else, some of us operating on a tight budget are looking for
inexpensive and simple solutions.

BTW, I look forward to reading ALL solutions and suggestions for issues,
even though it may not fit my situation. Keep the alternatives coming!

-John Clark (DiskDoctr)

"Normal" priority SMTP messages don't usually time out in that short a
period of time. "Urgent" messages might, but if they're urgent, why
would the originator want them to sit on a secondary MX until you get
around to getting your server back on line.

Quote:>If we reported it Mon am, it is possible that our mailserver has been
>unavailable for several days (Fri eve- Mon afternoon, assuming a quick fix
>to the T1 problem). A second server wouldn't help in this situation.

I think I'd be looking for another provider if that happened more than
once. Of course, if e-mail is that important, a second connection from
another provider would fix the problem and give you nice warm feeling
of redundancy.

Quote:>Our AV solution wouldn't have helped with the luv virus. It took several
>hours for Symantec to release a definition, and a good portion of our
>customer base (gov't) was spewing propagation messages wildly.

We all suffer from these problems, occasionally. Stopping the MTA
would have prevented any outbound leakage. Inbound mail could have
waited a few hours on the originator's servers until you had the new
signatures.

Quote:>Our ISP is very helpful and provides a number of addon services to
>compliment our own. They are happy to do it, and less overhead for us. For
>example, we host our website with the ISP instead of internally. No DMZ
>issues, no outage headaches, and most importantly, reduced cost.

HTTP and SMTP are pretty different. Letting someone else host your web
site is usually not a bad idea since they've already spent the money
to harden (you hope) their servers.

Quote:>The cost of
>a high bandwidth connection to support a website and all your corporate
>traffic vs the cost of having a high bandwidth ISP host your site, and not
>worrying about the Sat am calls because the mission critical website is down
>is heavily weighted towards using the service of the ISP.

Mission critical and outsourced don't usually go well together.

Quote:>I started and operated an ISP years ago. I sold it when the market was hot.
>The early am and weekend troubleshooting gets old really fast :-)

I spend over 20 years in tech support. Tell me about it.

Quote:>Bounced email happens. It depends upon the resend settings on the sending
>server, and the weekend scenario I mentioned could definitely exceed the
>typical 48hr threshold.

>You are correct in saying that unanswered emails can cause a similar poor
>impression. It's sort of like calling a business' telephone number and not
>getting an answer. That's bad. But it's worse to call and hear, "...number's
>been disconnected..."  Lesser of two evils, I guess.

But your server being offline would be the equivilent of "all our
circuits are busy", not a disconnected number. :)

Quote:>People like you with lots of knowledge and probably lots of resources can
>setup redundant solutions and creative configurations, and that's great.

Well, it's the company with the resources, not me. :)

Quote:>It
>probably works better. But I get the impression from reading many of the
>postings that there are a lot of people here who don't have you degree of
>knowledge and are looking for easy, cheap solutions.

If you find that combination, let me know. Most are hard and
expensive.

Quote:>Call your ISP and in
>about 5 minutes you're finished. They'll most likely have it up within a
>day. Doesn't get much easier :-)

I guess you haven't been reading all the problems /caused/ by ISP's,
then? I'll quote someone else: "All ISP's suck. Some just suck less
than others."

Quote:>Our ISP charges $25/month for the backup MX. In my book that's a nobrainer.
>Saves cost of server, hassle of outages, etc, etc.

Most folks here can't even find an ISP that'll handle SMTP at all!

Quote:>Basically, if you've got the extra server and resources, build a better
>solution. Else, some of us operating on a tight budget are looking for
>inexpensive and simple solutions.

An even cheaper solution is to find another company (or whatever)
that's willing to provide that service to you if you'll provide it to
them.

Quote:>BTW, I look forward to reading ALL solutions and suggestions for issues,
>even though it may not fit my situation. Keep the alternatives coming!

Always.

------------------
Rich Matheisen
MCSE+I, Exchange MVP
MS Exchange FAQ at http://www.swinc.com/resource/exch_faq.htm