Bypassing the ISP when they block SMTP protocol?

Bypassing the ISP when they block SMTP protocol?

Post by SC G » Sun, 26 Jun 2005 02:02:27



Hi,

I have some BSD boxes online as dedicated web/mail servers.
When traveling around I would like to be able to pop my mail
and then queue mail up from a dial up connection. I can pop
no problem..but some ISPs block port 25 from a dynamic
address which limits my outbound email.

I had thought of running a second copy of sendmail at a
non-standard port..but I'm not sure of any side effects of two
sendmails running. I can ssh in and use elm or similar
but I really would to use my normal mail agent from
any IP address.

Thanks for ideas. TVJ
 
 
 

Bypassing the ISP when they block SMTP protocol?

Post by james » Sun, 26 Jun 2005 02:09:20


ssh tunnel?
ssh -a -N -n -T -C -L25:SMTP_SERVER:25 localhost
or something along the lines..
point your mail client to localhost and it will forward across the
tunnel to port 25 on your server.

--
- - james <at> hal-pc.org - -

Polish-Dutch-Scottish-Irish-Cherokee-German-Coonass-American and proud
of it!
When will it end?
- - - - - - - - - - - - - - -

 
 
 

Bypassing the ISP when they block SMTP protocol?

Post by james » Sun, 26 Jun 2005 02:13:06


sorry.. had that backwards
shoud be "ssh <options> -L25:localhost:25 your_server"

--
- - james <at> hal-pc.org - -

Bigot = A Nationalist winning an argument with a Liberal.
- - - - - - - - - - - - - - -
 
 
 

Bypassing the ISP when they block SMTP protocol?

Post by SC G » Sun, 26 Jun 2005 02:37:24


My local client is windows-based. I have cygwin installed but
cannot get sshd to run. But I can figure it out. THANKS.
 
 
 

Bypassing the ISP when they block SMTP protocol?

Post by Grand Pooh » Sun, 26 Jun 2005 04:02:59

You just need an ssh client that is capable of port forwarding to connect to
your remote BSD machine as described. I prefer SecureCRT from VanDyke..
 
 
 

Bypassing the ISP when they block SMTP protocol?

Post by james » Sun, 26 Jun 2005 04:56:19


PuTTY works well. supports X forwarding and ssh tunnels. kinda screwy
way to do key based auth though...

--
- - james <at> hal-pc.org - -

"C code. C code run. Run code run... please!"
- - - - - - - - - - - - - - -
 
 
 

Bypassing the ISP when they block SMTP protocol?

Post by Jean-Yves » Sun, 26 Jun 2005 10:09:43


What I do against this kind of things is to simply make my mail server
listen on another port like 8025 and my laptop will use this server for
smtp out with the port 8025.

I have sendmail running with authentication to allow relaying.

Works perfectly, anywhere

Jean-Yves
 
 
 

Bypassing the ISP when they block SMTP protocol?

Post by SC G » Mon, 27 Jun 2005 04:34:46


This works perfectly. But I will also try the sendmail option
since it's a little cleaner. But until I am up and running!!
 
 
 

Bypassing the ISP when they block SMTP protocol?

Post by G. Paul Zi » Wed, 29 Jun 2005 22:55:00


You could submit your outbound mail via port 587. Recent sendmails
listen here for MUA->MTA communications.

--
G. Paul Ziemba
FreeBSD unix:
6:31AM up 172 days, 6:18, 12 users, load averages: 0.27, 0.14, 0.04
 
 
 

Bypassing the ISP when they block SMTP protocol?

Post by John Prath » Thu, 30 Jun 2005 04:38:51


Port 465/tpc is noted as SMTP over TLS, and is quite an appropriate port
to tell sendmail to listen on as well, though TLS should be enabled. :)

I'm a big fan of SMTP/TLS and IMAP/SSL on server side, so I can just
tell my clients to use encryption always, no mess with ssh, and the port
465 one wasn't blocked by my ISP that blocked port 25.

If you can't do TLS/SSL it's no matter. Have mail client listen on any
port you like. I've had postfix listen on 25, 465, and 25025 all at
once happily.

You probably want to find a way to make the one sendmail process run on
more ports, rather than running multiple instances of sendmail.


-john