POP3 and Bridge-Mode Configuration

The REDDOXX appliance can be used to fetch e-mail via POP3.

POP3 fetching can be used in two different operating modes, in standard mode and bridge mode.

In standard mode the REDDOXX appliance is connected via a LAN interface (LAN-1).

In bridge mode the appliance is set up physically between the internet gateway (firewall/router) and the subsequent switch.
You connect the gateway with the LAN port 1 and the subsequent LAN (switch) with the LAN port 2.
The advantage of using the bridge mode is that there is no need to adjust your existing infrastructure in order to both retrieve your e-mails via POP3 and send them via SMTP.
Keep in mind, that the entire internet traffic will be processed by the appliance, this could cause issues while performing maintenance on the appliance, as the internet connection to the clients is lost when doing maintenance or reboots.

  1. An E-Mail Client starts a pop3 poll
  2. The Reddoxx takes stores the login credentials
  3. The Appliance provides all e-mails to the client that are already in the "POP3 Out Queue", this ends the poll request from the client
  4. The Appliance uses to login credentials to fetch mails from the mail provider
  5. All available messages are fetched and moved to the "POP3 In Queue"
  6. The Validiation Process filters for spam and archives E-Mails if the MailDepot archiving is enabled
  7. In the last step, E-Mails are moved to the POP3 Out Queue and are ready to be fetched by the e-mail Client

When recieving E-Mails via pop3 with the Reddoxx Appliance, the delivery takes place in the 2nd poll from the e-mail Client.
 
Example:
E-Mails are fetched every 5 minutes via the E-Mail client.
The mail will reach the client after 10 minutes, as the mail is validated and stored in the appliance before.
 
CISS:
With this, this behaviour causes the CISS Challenge to be delivered to the Sender, when the E-Mail is fetched by the POP3 Client.
When fetching Mails with a centralized POP3 fetching Service (e.g. fetchmail, POPCon), no Problems will occur.
If the fetching is done via single E-Mail Clients (e.g. after a User is back from Holiday), the CISS Challenge is delivered with a delay.

The following steps are required to configure Mail Clients to recieve POP3 E-Mails via the Reddoxx Appliance:

  1. Set the hostname or IP adress of the Appliance as incoming POP3 mail server
  2. The account name is created with the login name and the pop3 Server from the provider
    • Example 1:
    • Your E-Mail Address is: myaccount@web.de
    • The Login is: myaccount
    • The Pop3-Server is: pop3.web.de
    • This results in the new account name: myaccount@pop3.web.de
    • Example 2:
    • Your E-Mail Address is: myaccount@gmx.de
    • The Login is: myaccount@gmx.de
    • The Pop3-Server is: pop3.gmx.de
    • This results in the new account name: myaccount@gmx.de@pop3.gmx.de
  3. Please use this compound account name for logging on to your REDDOXX appliance via POP3
  4. Disable "Server authentication" for Outgoing Server when outgoing mails are to be delivered via the Reddoxx Appliance

When fetching E-Mail via pop3 with the Reddoxx Appliance, Mails are alway deleted from the Mail Server, even if the client is configured not to delete Mails from the Server!

The following steps are required to configure the Appliance for sending Mails via SMTP:

  1. Configure all sending hosts in Trusted Networks (Configuration -> E-Mail Transport -> Trusted Networks)
  2. Enter the IP Address for a local network or a single host
  3. Enter the corresponding netmask, single Hosts (internal mailservers) have to be configured with 255.255.255.255 as network mask
  4. Confirm the settings with "Save"
  5. Restart the service SMTP Server to apply the changes

The following steps are required to configure the Appliance for sending Mails via SMTP Relay (in case there is no static IP):

  1. Configure the SMTP SMTP Relay in den SMTP Settings (Configuration -> E-Mail Transport -> SMTP Settings -> Client Settings)
  2. If a relay is used and needs a tcp port other than 25, the portnumber can be provided after the relay server address (e.g. my.mailserver.com:587)
  3. Finish the configuration with "Apply Settings" and restart the SMTP Server and SMTP Client services

The following steps are required to Archive outgoing E-Mail:

  1. Enter the Sender Address Domain in local domains (Configuration -> E-Mail Transport -> Local Domains)
  2. If using E-Mail Addresses vom Providers beside your own local Domain, these Need to be configured in local domains too, to enable archiving.

Please connect your appliance via the LAN-1 interface according to the information given in standard mode, first.
Enable Ethernet Bridge Mode in the network configuration (Configuration -> Appliance -> Network -> Network Interfaces)

When operating in bridge mode the TCP connections of the ports for SMTP (25), POP3 (110) and POP3s (995) are being intercepted and processed by the REDDOXX appliance.´
All other protocols will be routed in the original way.

In bridge mode the appliance is set up physically between the internet gateway (firewall/router) and the subsequent switch.
You connect the gateway with the LAN port 1 and the subsequent LAN (switch) with the LAN port 2.
Please keep in mind that the internet connection will be lost for a short time during the physical connection process.

Use a cross-cable to connect the appliance with the firewall

Bridge policies are configured in the appliance configuration (Configuration -> Appliance -> Bridge Policies).
Here you can define the policies that exclude certain members (mail clients) or internet mail servers from proxy mode.
This means that the internet traffic for these members is being processed unconsidered and unaltered.

Thanks to the policies you have the opportunity to combine various rules.
These rules are processed top down.
As soon as a rule applies, it will be used. Further subsequent rules will not be regarded anymore.

Setting up users and e-mail aliases is done automatically as soon as a client retrieves an e-mail from its provider.
Thereby the e-mail alias receives the pseudo domain pop3proxy.reddoxx.
Licences will be assigned automatically, depending on whether there are still any available.

Consider when using catch-all mailboxes, that all E-Mail Addresses are assigned to a single User (Login)
This results in the problem, that only one user in the appliance is configured having all E-Mail aliases.
The waiting Queues therefore can only be managed by this one single User (Login).
Solution:
Create local users and assign the e-mail addresses accordingly.

Archiving of outgoing E-Mails
For a user to be able to see his outgoing e-mails int he Archive, the e-mail address needs to be assigned to the User manually.
Make sure that the domain for this E-Mail address is configured in the local Domains.

For logging on to the USER console please choose the same user name that you defined for the POP3 login.
Please keep in mind that ‘@’ within your user name must be replaced by ‘+’.
The password is exactly the same that you use with your provider.

In appliance administration -> Mail Queues you can see, whether there is a message still in the appliance.
In the POP3 In Queue you can find the messages that have been retrieved by the REDDOXX appliance but have not been processed yet.
In the POP3 Out Queue you can find the messages that have already been processed by the REDDOXX appliance but have not been retrieved by a client yet.