POP3 proxy to bypass a firewall? - Help

This is a discussion on POP3 proxy to bypass a firewall? - Help ; I'm working at a customer site that blocks outbound POP3. I cannot reach my ISP. I have root access to an external linux server with OpenSSH. (I _CAN_ SSH to this box from client site). I DO NOT have SSH ...

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Thread: POP3 proxy to bypass a firewall?

  1. POP3 proxy to bypass a firewall?

    I'm working at a customer site that blocks outbound POP3. I cannot
    reach my ISP. I have root access to an external linux server with
    OpenSSH. (I _CAN_ SSH to this box from client site). I DO NOT have
    SSH to the ISP POP3 server.

    What combination of SSH tricks and any POP3 proxy can I use to get
    access to the ISP's POP3 port 110?

  2. Re: POP3 proxy to bypass a firewall?

    On 1 Jun 2004 06:48:58 -0700, isp@derdev.com (Dave Richardson) wrote:

    >I'm working at a customer site that blocks outbound POP3.


    I wish I had an answer instead of a question: why? What possible
    justification is there for this?

    --
    Joe Zeff
    The Guy With the Sideburns
    The point here is that there are stupid people all over.
    http://www.lasfs.org http://home.earthlink.net/~sidebrnz

  3. Re: POP3 proxy to bypass a firewall?

    Dave Richardson wrote:

    > I'm working at a customer site that blocks outbound POP3.


    .... pop3 is not outbound, unless you're sitting
    at the server and client boxes are accessing it
    ..
    --
    << http://michaeljtobler.homelinux.com/ >>
    God is a comic playing to an audience that's afraid to laugh.


  4. Re: POP3 proxy to bypass a firewall?

    On Tue, 01 Jun 2004 22:24:53 GMT, mjt
    wrote:

    >... pop3 is not outbound, unless you're sitting
    >at the server and client boxes are accessing it


    The client makes *outgoing* requests to the server, and I suspect
    that's what they block.

    --
    Joe Zeff
    The Guy With the Sideburns
    "Always there are two, the BOFH and the PFY."
    http://www.lasfs.org http://home.earthlink.net/~sidebrnz

  5. Re: POP3 proxy to bypass a firewall?

    Joe Zeff wrote:

    >>... pop3 is not outbound, unless you're sitting
    >>at the server and client boxes are accessing it

    >
    > The client makes outgoing requests to the server, and I suspect
    > that's what they block.


    .... hmmm. i walked into that one, eh?
    ..
    --
    << http://michaeljtobler.homelinux.com/ >>
    Remember, even if you win the rat race -- you're still a rat.


  6. Re: POP3 proxy to bypass a firewall?

    Joe Zeff wrote in message news:...
    > On Tue, 01 Jun 2004 22:24:53 GMT, mjt
    > wrote:
    >
    > >... pop3 is not outbound, unless you're sitting
    > >at the server and client boxes are accessing it

    >
    > The client makes *outgoing* requests to the server, and I suspect
    > that's what they block.


    Yes, that's correct, the OUTBOUND request to port 110 is being
    blocked. I do not care to ask why, the paranoia is a bit high around
    here. So anyways, how can I "forward" my port 110 requests through
    another host via SSH port forwarding?

    Still need the help...

  7. Re: POP3 proxy to bypass a firewall?

    Dave Richardson wrote:

    > I'm working at a customer site that blocks outbound POP3. I cannot
    > reach my ISP. I have root access to an external linux server with
    > OpenSSH. (I _CAN_ SSH to this box from client site). I DO NOT have
    > SSH to the ISP POP3 server.
    >
    > What combination of SSH tricks and any POP3 proxy can I use to get
    > access to the ISP's POP3 port 110?


    Not exactly a linux problem, but...

    A 2 part proxy.

    Client side is a program that presents itself as the server. When it
    gets a request it connects via an available channel (SSH, HTTP, ...) to
    a second program on the other side of the firewall that presents itself
    as a client to the real server. The proxy doesn't even have to know to
    protocol being forwarded.

    I've recently been involved in a project using HTTP(S) as a transport
    layer through a paranoid firewall. a definate lag, though tolerable for
    the app. An SSH or other persistant connection transport layer would be
    prefered for most uses.

    cal at splitreflection dot com

  8. Re: POP3 proxy to bypass a firewall?

    On Wed, 02 Jun 2004 09:24:47 -0700, penguinista
    wrote:

    >Not exactly a linux problem, but...


    Here's another thought. Have your linux box collect your mail via
    POP3. Then, set up a POP server on it, listening on J. Random Port,
    and set your client at ork to use that instead of 110. (1110 would be
    reasonable, as it's exactly 1000 higher than the standard.)

    --
    Joe Zeff
    The Guy With the Sideburns
    "Always there are two, the BOFH and the PFY."
    http://www.lasfs.org http://home.earthlink.net/~sidebrnz

  9. Re: POP3 proxy to bypass a firewall?

    Dave Richardson wrote:

    >> The client makes outgoing requests to the server, and I suspect
    >> that's what they block.

    >
    > Yes, that's correct, the OUTBOUND request to port 110 is being
    > blocked.**I*do*not*care*to*ask*why,*the*paranoia*i s*a*bit*high*around
    > here.**So*anyways,*how*can*I*"forward"*my*port*110*requests*through
    > another host via SSH port forwarding?


    .... how about setting up the Linux box to capture the
    email, then set your POP server on that Linux box to
    listen on port 80 or 8080
    ..
    --
    << http://michaeljtobler.homelinux.com/ >>
    He looked at me as if I was a side dish he hadn't ordered.


  10. Re: POP3 proxy to bypass a firewall?

    Joe Zeff wrote in message news:<439sb05qlfv87dsr40erq8ufj1uv5u7ot1@4ax.com>...
    > On Wed, 02 Jun 2004 09:24:47 -0700, penguinista
    > wrote:
    >
    > >Not exactly a linux problem, but...

    >
    > Here's another thought. Have your linux box collect your mail via
    > POP3. Then, set up a POP server on it, listening on J. Random Port,
    > and set your client at ork to use that instead of 110. (1110 would be
    > reasonable, as it's exactly 1000 higher than the standard.)


    Hrm, all good BUT.. .(you knew that was coming)...
    I move around enough that I don't want this server picking up _all_ my
    POP3 email. I just want to proxy through it to reach the ISP.
    Obviously when I'm out wifi or at home or elsewhere I can and _want_
    to POP3 directly to the ISP. I don't want to run my own mail server
    anymore...

    More help welcome, past suggestions appreciated!

  11. Re: POP3 proxy to bypass a firewall?

    On 3 Jun 2004 08:47:43 -0700, isp@derdev.com (Dave Richardson) wrote:

    >Obviously when I'm out wifi or at home or elsewhere I can and _want_
    >to POP3 directly to the ISP.


    So just ssh in to turn it on when you need it, and turn it back off
    when you don't.

    --
    Joe Zeff
    The Guy With the Sideburns
    "Always there are two, the BOFH and the PFY."
    http://www.lasfs.org http://home.earthlink.net/~sidebrnz

  12. Re: POP3 proxy to bypass a firewall?

    Joe Zeff wrote in message news:...
    > On 3 Jun 2004 08:47:43 -0700, isp@derdev.com (Dave Richardson) wrote:
    >
    > >Obviously when I'm out wifi or at home or elsewhere I can and _want_
    > >to POP3 directly to the ISP.

    >
    > So just ssh in to turn it on when you need it, and turn it back off
    > when you don't.


    Just released a client that should help.
    http://www.digitallabs.net/tm
    You'd configure it so that you enter the normal SSH information to the
    linux server, and then setup the Mail server to be the ISP's mail
    server. Then use IMAP instead of POP3 so you don't have to worry
    about downloading your mail. Hope this helps...
    Chad Amberg
    http://www.digitallabs.net

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