Bypass SMTP mail

lee von · 08-04-2008, 08:15 AM

I work for a company that blocks outgoing SMTP mail. I can't get an exemption. I use TBird for my personal mail account at work. I can check incoming, but have to go to a web interface to send. Any thoughts on a workaround? Could I use my Mac server at home to forward to the SMTP service?

cwtnospam · 08-04-2008, 08:28 AM

How do they expect users to send mail? Are they using Exchange?

lee von · 08-04-2008, 08:29 AM

Internally, there is an Exchange server for business email. I just want to be able to use my personal account at work.

cwtnospam · 08-04-2008, 08:43 AM

Quote:

Originally Posted by lee von


	Could I use my Mac server at home to forward to the SMTP service?

Is it OS X Server, or OS X with sharing turned on?

lee von · 08-04-2008, 08:46 AM

10.4 Server. I have an old 450 G4, still seems to be up to most tasks I toss at it. Good high-speed connection as well. Could I set it up as a mail server, but have it forward to my personal account (1and1)? It would only work if I can send via something other than SMTP from work.

operator207 · 08-04-2008, 08:57 AM

Companies block this type of activity for a reason. What are the chances of you getting "caught" doing this, and what is the punishment for violating this block?

Weigh that in with your work around. They could easily, because your circumventing their firewall and policies, fire you for that activity.

With that being said, try sending mail on port 587. Its not normally blocked by firewalls and most SMTP servers will answer on port 587.

baf · 08-04-2008, 08:59 AM

at work:
ssh -L 25:your_normal_smtp:25 homeuser@your_mac_at_home
point your mail client at localhost
at home enable remote login

lee von · 08-04-2008, 09:04 AM

op-
If I were using a workaround to send out spam, that would be an issue. From what our IT group says, I would be fine. If my personal account's provider offered an exchange server to send email to, I would just use that.

baf-
Not sure I know how to use many terminal commands, I assume that is what you mean.

cwtnospam · 08-04-2008, 09:15 AM

Quote:

Originally Posted by baf


	ssh -L 25:your_normal_smtp:25 homeuser@your_mac_at_home point your mail client at localhost at home enable remote login

Yes, it's in the Terminal:
ssh -L ----> binds port 25 on your machine to go through your mac at home to your home's smtp server. The traffic between work and home is through port 22, and not seen by work as smtp.

I'm wondering if this requires OS X server on the home machine, or can any Mac do it?

agentx · 08-04-2008, 01:24 PM

any mac has either Sendmail (OS 10.1, 10.2,10.3) or Postfix (10.4, 10.5 ) built in which effectively a fully featured mail server.

I personally would try port 587 but if your admins are well savvy they would have blocked this anyway and will certainly notice it in firewall logs. I block 25, 465, 587 at client premises that require only their SMTP mail server to be used.

Also as above if they want to block personal email and you have asked for access and been told no then you are in breach of your IT rules.

cwtnospam · 08-04-2008, 01:36 PM

Quote:

Originally Posted by savage


	...if they want to block personal email and you have asked for access and been told no then you are in breach of your IT rules.

Of course, if you send mail from your phone, then IT has no say. Maybe it's time to get an iPhone.

lee von · 08-04-2008, 01:39 PM

Crackberry here

iPhone would have been a nice option!

Webmail from any provider (Google, Yahoo, 1and1...) I know if is allowed internally, just the SMTP is blocked. I can't send through any port, SMTP is blocked company-wide.

How would I go about bouncing the email off my home server?

cwtnospam · 08-04-2008, 01:41 PM

Quote:

Originally Posted by lee von


	How would I go about bouncing the email off my home server?

See post #7

lee von · 08-04-2008, 01:49 PM

In Terminal, I get:

Quote:


	Privileged ports can only be forwarded by root.

Not sure what to do now.

cwtnospam · 08-04-2008, 01:54 PM

Quote:

Originally Posted by lee von


	Not sure what to do now.

Punt, unless you've got admin access.

baf · 08-04-2008, 01:59 PM

Oh sorry forgot that:
ssh -L 2525:your_normal_smtp:25 homeuser@your_mac_at_home
point your mail client at localhost smtp port=2525

lee von · 08-04-2008, 02:03 PM

I think it worked, I don't get a result in Terminal, though. I'll look at my home server tonight.

cwtnospam · 08-04-2008, 02:16 PM

Quote:

Originally Posted by lee von


	I think it worked, I don't get a result in Terminal, though. I'll look at my home server tonight.

If it worked you should be able to send your work address an email from your home address.

NovaScotian · 08-04-2008, 02:43 PM

As a slight variation on this theme, I use baf's scheme to both read and send personal mail when I'm away. I let Eudora collect my mail at home (because my ISP won't save much, so I have to keep downloading mail and deleting it from my pop mail account) and when I'm away I use VNC to both read it and send replies. This avoids having some of my mail on my home machine and some on my laptop. Years ago (before VNC or OS X), I used Timbuktu.

08-04-2008, 08:15 AM	#1
lee von Triple-A Player Join Date: Jul 2007 Posts: 76	Bypass SMTP mail I work for a company that blocks outgoing SMTP mail. I can't get an exemption. I use TBird for my personal mail account at work. I can check incoming, but have to go to a web interface to send. Any thoughts on a workaround? Could I use my Mac server at home to forward to the SMTP service?

08-04-2008, 01:59 PM	#16
baf MVP Join Date: Jun 2007 Location: Skellefteå, Sweden Posts: 1,173	Oh sorry forgot that: ssh -L 2525:your_normal_smtp:25 homeuser@your_mac_at_home point your mail client at localhost smtp port=2525 __________________ /Bengt-Arne Fjellner IT-Administrator Luleå university, Sweden. Some say: "You learn as long as you live". My way: "You live as long as you learn". Last edited by baf; 08-04-2008 at 02:26 PM. Reason: sh should be ssh

08-04-2008, 02:43 PM	#19
NovaScotian Hall of Famer Join Date: Oct 2002 Location: Halifax, Canada Posts: 4,946	As a slight variation on this theme, I use baf's scheme to both read and send personal mail when I'm away. I let Eudora collect my mail at home (because my ISP won't save much, so I have to keep downloading mail and deleting it from my pop mail account) and when I'm away I use VNC to both read it and send replies. This avoids having some of my mail on my home machine and some on my laptop. Years ago (before VNC or OS X), I used Timbuktu. __________________ 17" MBP, OS X 10.8.3; 27" iMac, OS X 10.8.3

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08-04-2008, 08:28 AM	#2
cwtnospam League Commissioner Join Date: Jan 2005 Posts: 8,475	How do they expect users to send mail? Are they using Exchange?

08-04-2008, 08:29 AM	#3
lee von Triple-A Player Join Date: Jul 2007 Posts: 76	Internally, there is an Exchange server for business email. I just want to be able to use my personal account at work.

08-04-2008, 08:46 AM	#5
lee von Triple-A Player Join Date: Jul 2007 Posts: 76	10.4 Server. I have an old 450 G4, still seems to be up to most tasks I toss at it. Good high-speed connection as well. Could I set it up as a mail server, but have it forward to my personal account (1and1)? It would only work if I can send via something other than SMTP from work.

08-04-2008, 08:57 AM	#6
operator207 Major Leaguer Join Date: Jan 2007 Posts: 446	Companies block this type of activity for a reason. What are the chances of you getting "caught" doing this, and what is the punishment for violating this block? Weigh that in with your work around. They could easily, because your circumventing their firewall and policies, fire you for that activity. With that being said, try sending mail on port 587. Its not normally blocked by firewalls and most SMTP servers will answer on port 587.

08-04-2008, 08:59 AM	#7
baf MVP Join Date: Jun 2007 Location: Skellefteå, Sweden Posts: 1,173	at work: ssh -L 25:your_normal_smtp:25 homeuser@your_mac_at_home point your mail client at localhost at home enable remote login __________________ /Bengt-Arne Fjellner IT-Administrator Luleå university, Sweden. Some say: "You learn as long as you live". My way: "You live as long as you learn".

08-04-2008, 09:04 AM	#8
lee von Triple-A Player Join Date: Jul 2007 Posts: 76	op- If I were using a workaround to send out spam, that would be an issue. From what our IT group says, I would be fine. If my personal account's provider offered an exchange server to send email to, I would just use that. baf- Not sure I know how to use many terminal commands, I assume that is what you mean.

08-04-2008, 01:24 PM	#10
agentx Hall of Famer Join Date: Feb 2003 Location: Brighton, UK Posts: 3,811	any mac has either Sendmail (OS 10.1, 10.2,10.3) or Postfix (10.4, 10.5 ) built in which effectively a fully featured mail server. I personally would try port 587 but if your admins are well savvy they would have blocked this anyway and will certainly notice it in firewall logs. I block 25, 465, 587 at client premises that require only their SMTP mail server to be used. Also as above if they want to block personal email and you have asked for access and been told no then you are in breach of your IT rules.

08-04-2008, 01:39 PM	#12
lee von Triple-A Player Join Date: Jul 2007 Posts: 76	Crackberry here iPhone would have been a nice option! Webmail from any provider (Google, Yahoo, 1and1...) I know if is allowed internally, just the SMTP is blocked. I can't send through any port, SMTP is blocked company-wide. How would I go about bouncing the email off my home server?

08-04-2008, 02:03 PM	#17
lee von Triple-A Player Join Date: Jul 2007 Posts: 76	I think it worked, I don't get a result in Terminal, though. I'll look at my home server tonight.