I setup a mail server which has a convenient web interface on a computer connected to my ARDEN node. That node is tunneled in to the Southern California region. The name of my server is km6zpo-winlink.local.mesh. (It's called that because I'm also running an RMS Relay on it)
t's simple enough using the web interface to send emails back and forth on the server since essentially those message are staying on the same server.
For example:
user1@km6zpo-winlink.local.mesh can send to user2@km6zpo-winlink.local.mesh - that's easy.
Assuming that two separate mail servers could "see" each other by way of the AREDN network, is it possible for a user on one system to send an email to a user on another system?
For example:
mark@kmzpo-winlink.local.mesh send to someuser@somedomain.local.mesh
Has anyone tried this? Does anyone have a mail server running for me to test? (Check to see if you can "see" my mail server first: http://km6zpo-winlink.local.mesh )
Mark Warrick
KM6ZPO
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Mail Server to Mail Server via AREDN MESH - Possible? How?
Mon, 07/12/2021 - 16:03
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km6zpo
Mail Server to Mail Server via AREDN MESH - Possible? How?
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So this leads me to my next question, which I am testing now. Let's say we have three mail servers A, B and C. A and B can talk to each other and B and C can talk to each other. So, can I use server B in this scenario as a Smart Host to relay a message from A to C ? That's my current test. I'll report back whether or not it succeeded.
NOW, here's where this gets interesting... If I can route email to another server ON the mesh, what's to stop me from routing messages OFF the mesh? Why would I want to do that? Well let's assume the Internet backbone for Southern California went down and all cell and phone service went down. I have really a couple options: I could send a Winlink message through RMS relays via the mesh. We all know how to do that. But that requires special software (and a ham license) and it requires training. Everybody knows how to use email. So presumably I can send emails across the RF connected mesh (locally - all across the region) to any email server in the area.
P.S. MailEnable has a pretty nice web interface. You don't even need a separate webmail client. So that means it's platform independent on the client side. I'll setup an account for you to check it out, Jim and email you the login info. Go to: http://km6zpo-winlink.local.mesh/
To send from one mesh connected server to another mesh connected server, you need to first make sure that the two servers are able to talk to each other. I know, for example, that you would not be able to send a message from your server to mine because I can't see any of your nodes (kc4jir). Look through your mesh status page - find somebody in your area of the mesh who has a mail server running and contact them directly.
Once you know which server and account to send to, it's a simple as normal email. For example, if you were able to "see" my mail server, you could send a message to km6zpo@km6zpo-server.local.mesh
The part before the @ symbol is the account name. The part after the @ symbol is the server name.
Hope that helps, sorry I can't help you test.
---mark, KM6ZPO
Email on the mesh is basically the same as email on the Internet. I think what you're missing here is a basic understanding of how email works. This website and many others like it will be helpful: https://www.makeuseof.com/tag/technology-explained-how-does-an-email-ser...
If you are trying to send email from a MESH-connected server to an external email server (for example, somebody's hospital email account), MESH email is not the best idea. While you CAN send email out, they will not be able to simply hit reply to get a message back to you. This is because the MESH is its own "internet" of sorts. The domain name local.mesh does not exist on the Internet. So when their email servers try to locate {yourname}@{yourmeshserver}.local.mesh, it won't be found. Similarly, if two email servers are on disparate parts of the MESH, the same problem will happen.
But let's say you all decide that external users (i.e. hospital staff) and licensed ham operators are willing to use the same web-based email server. MailEnable makes that possible and that's how I have things setup. On the WAN (internet side), users can login to the email server at http://mail.km6zpo.com/Mondo/lang/sys/login.aspx . On the MESH side of that same email server. licenses operators would use this link to login: http://km6zpo-server.local.mesh/MEWebmail/Mondo/lang/sys/login.aspx
Each person needs to have an account on MY email server, whether they are accessing it from outside or inside the MESH. External users cannot simply setup an email client to point to my server - why? Same as noted above. Because they are outside the mesh, any messages TO a server on the MESH would go nowhere. BUT, so long as they login to the web interface, communications can happen. And that's a good thing because no involvement from the hospital's IT staff is required. And I guarantee you, the average user has NO CLUE about how to setup an email client. Even if you give them step by step instructions, most are going to opt to use the web interface anyway.
So, before we dig deeper, perhaps you can discuss your use case exactly. Keep in mind, external users (hospitals, etc.) are NOT going to be able to send messages to the MESH.
---mark, KM6ZPO
Mark,
Thanks for the reply and the links. All the services I am developing and testing are mesh only -- no external customers -- and don't rely on the internet. I look at the mesh as a intranet so what I am trying to get going is an email service for node computers strictly on the MESH.-- so I guess you could call in intranet email.
The mesh and the services are designed to be used by hams and will be setup by hams.The EOC and Hospitals have ARES members assigned.
So in essence I was looking at a stand alone email server with email accounts populated ( same domain) and hosted on one of the mesh nodes. Then the node computers would have email clients setup to process email on the mesh.
I will admit email is out of of lane a bit since I have never tackled it. So all the help you can give is appreciated. I have started looking at the webmail capability of mailenable Didn't have any luck with IMAP/POP and SMTP setup connecting to a server on one of my modes.
Thanks for your interest in helping out.
Dave Bury
KC4JIR
Hi Dave,
Here's your solution: put a HAP AC Lite at each location that needs access to your email server. Tunnel each one (via the Internet initially, but plan to build out an AREDN RF infrastructure) to that location. Then each location will be able to access that mail server, whether that be through the web interface or by setting up email clients. You don't need multiple mail servers.
NOTE: If you don't setup the RF links between facilities, and the Internet goes down, you'll lose your tunnels and the remote locations won't have access to email. That's why you need to start building out the RF infrastructure - so that no location is dependent upon the Internet working.
PS. Winlink will accomplish all of the above and already has an infrastructure in place to support everything you're trying to do. Since every one of your operators is going to be a licensed operator, there really is no need for a mail server.
---mark, KM6ZPO
We will eventually build out the RF mesh when we outfit the EOC and Hospitals. They have requested a design and estimated cost but we wanted to tunnel for now to learn and play.
So thanks very much for sticking with me! I'm hosting RMS Relay for a Telnet Post Office and we run Telnet P2P sometimes.
Thanks,
Dave
KC4JIR
"I thought the mailenable server would operate in a client-server configuration by making the server IP the same as the node lan ip."
Since 'mailenable' is a Microsoft Windows OS application,
the computer running 'mailenable' should not have the same IP address as the node (an OpenWRT/AREDN OS)
(from which it is getting its IP address (via DHCP)).
What am I missing?
Chuck
"what is the settings so email could be sent and received across the MESH."
Hi, Dave:
I am not sure what you mean when you refer to 'the MESH'.
I assume that your 'the MESH' is 2 or more AREDN devices linked by RF or DtD or 'tunnel'.
Email from a client application would be sent to an email server application advertised on a node on your 'the MESH'.
Chuck
Normally mail servers rely on DNS MX records to figure out which server to connect to when delivering email. The problem here is that aredn doesn't really use traditional DNS for the .mesh TLD. Olsrd finds nodes and populates a text file .. much like the contents of an etc/hosts file .. and then dnsmasq looks in that file to see if there are any matches when lookups are executed. If that fails, dnsmasq will try to reach out to traditional dns servers. However since the .mesh TLD doesn't actually exist, dnsmasq will fail any type of additional lookup (such as for an MX record).
That means if you want to deliver emails to different .mesh nodes, you'd need to take that olsrd node data and write rules for your email server so that it knows where to connect for delivery. I think that could be automated with a script, assuming each node knows about all the other nodes. However, if there are nodes that want email but aren't hosting their own email server, things get tricky because somehow your email server would need to know where to deliver to instead (This is why MX records are so useful). One possible workaround would be for each node to either host their own email server, or have some additional iptables rules on each node that would forward incoming port 25 traffic to the mail server that will accept their mail.
As for delivering to the outside world, that is possible, however it would require three things -- one, a node with an email service that is able to traverse the wan port (a setting we can enable through the aredn gui). Two, you would need to own a domain name that you would use in place of your local.mesh address because most mail servers will reject source emails with domains that don't exist. Some mail servers can re-write the to and from addresses as they process the emails, so jimmy@callsign.local.mesh would become jimmy@real.domain.name.com. Three, you may need to use a mail relay depending on what kind of internet connection you have --thanks to spammers, most isps actively block port 25 outgoing traffic, and most receiving mail servers are outright hostile to traffic that is designated as belonging to non-corporate environments.