nanog mailing list archives
Re: Is your ISP blocking outgoing port 25?
From: Charles Wyble <charles () thewybles com>
Date: Thu, 18 Jun 2009 12:52:45 -0700
Zhiyun Qian wrote:
It has been long heard that many ISPs block outgoing port 25 for the purpose of reducing spam originated from their network.
Well blocking or redirecting to there servers, which have an undocumented filtering policy. All one needs to do in order to bypass that is use a vpn. Something lightweight like n2n could be used by the bot herders of the world.
I worked for a company that sent out several hundred thousand messages per day (an online card/invitations company). We ran spam assassian on our outbound farm, to prevent folks from using us to send spam. I presume the large service providers do the same.
AT&T is the major one that I know of that is still enforcing this policy.But they said they can unblock port 25 upon request. I am not sure how easy it is.
It's trivial. A web form. You get the link when you try to send mail to port 25 anywhere else. At least with Yahoo/SBC dsl.
I got the business class DSL from AT&T and no such nonsense exists.
Current thread:
- Is your ISP blocking outgoing port 25? Zhiyun Qian (Jun 18)
- RE: Is your ISP blocking outgoing port 25? Paul Stewart (Jun 18)
- Re: Is your ISP blocking outgoing port 25? Charles Wyble (Jun 18)
- RE: Is your ISP blocking outgoing port 25? Paul Stewart (Jun 18)
- Re: Is your ISP blocking outgoing port 25? Charles Wyble (Jun 18)
- Re: Is your ISP blocking outgoing port 25? Charles Wyble (Jun 18)
- Re: Is your ISP blocking outgoing port 25? Paul M Moriarty (Jun 19)
- Re: Is your ISP blocking outgoing port 25? Joe Provo (Jun 18)
- Re: Is your ISP blocking outgoing port 25? Lyndon Nerenberg (Jun 18)
- Re: Is your ISP blocking outgoing port 25? Christopher Morrow (Jun 18)
- Re: Is your ISP blocking outgoing port 25? Jack Bates (Jun 18)
- Re: Is your ISP blocking outgoing port 25? Jeroen Wunnink (Jun 19)
- Re: Is your ISP blocking outgoing port 25? Patrick W. Gilmore (Jun 19)
- Re: Is your ISP blocking outgoing port 25? Jeroen Wunnink (Jun 19)
- Re: Is your ISP blocking outgoing port 25? Sean Donelan (Jun 19)
- Re: Is your ISP blocking outgoing port 25? Steven King (Jun 19)
- Re: Is your ISP blocking outgoing port 25? Lyndon Nerenberg (Jun 18)
- RE: Is your ISP blocking outgoing port 25? Paul Stewart (Jun 18)