nanog mailing list archives
Re: ISP port blocking practice
From: Joe Maimon <jmaimon () ttec com>
Date: Thu, 22 Oct 2009 20:45:56 -0400
Sean Donelan wrote:
On Thu, 22 Oct 2009, Lyndon Nerenberg (VE6BBM/VE7TFX) wrote:My experience is that port 587 isn't used because ISPs block it out-of-hand. Or in the case of Rogers in (at least) Vancouver, hijack it with a proxy that filters out the AUTH parts of the EHLO response, making the whole point of using the submission service ... pointless.You mentioned this last June. Can anyone else corroborate it? Rogers says they don't do that, and lots of other people seem to be able touse port 587 on Rogers (and other ISPs) without problems.All the cases I've looked at, where someone claimed an ISP was blocking port 587, it turned out to be some other problem. The most common reason was related to some security software/host based firewall running on the user's own computer.
First thing to check when "email is stuck in my outbox"Next is to check whether outlook is trying to do SMTPS on 587 instead of STARTTLS. Hence 465 SMTPS port workaround.
Current thread:
- ISP port blocking practice Zhiyun Qian (Oct 22)
- Re: ISP port blocking practice Antonio Querubin (Oct 22)
- Re: ISP port blocking practice Valdis . Kletnieks (Oct 22)
- Re: ISP port blocking practice Ricky Beam (Oct 22)
- Re: ISP port blocking practice Justin Shore (Oct 22)
- Re: ISP port blocking practice Lyndon Nerenberg (VE6BBM/VE7TFX) (Oct 22)
- Re: ISP port blocking practice Sean Donelan (Oct 22)
- Re: ISP port blocking practice Joe Maimon (Oct 22)
- Re: ISP port blocking practice Steve Bertrand (Oct 22)
- Re: ISP port blocking practice Lyndon Nerenberg (VE6BBM/VE7TFX) (Oct 23)
- Re: ISP port blocking practice Chris Boyd (Oct 23)
- Re: ISP port blocking practice Lyndon Nerenberg (VE6BBM/VE7TFX) (Oct 22)
- Re: ISP port blocking practice Justin Shore (Oct 22)
- Re: ISP port blocking practice Joe Maimon (Oct 22)
- Re: ISP port blocking practice Justin Shore (Oct 22)
- Re: ISP port blocking practice Scott Howard (Oct 22)
- Re: ISP port blocking practice Owen DeLong (Oct 22)
- Re: ISP port blocking practice Chris Boyd (Oct 23)
- Re: ISP port blocking practice Jack Bates (Oct 23)