nanog mailing list archives
Re: Outgoing SMTP Servers
From: Dave CROCKER <dhc2 () dcrocker net>
Date: Tue, 25 Oct 2011 11:27:37 +0200
On 10/25/2011 8:13 AM, William Herrin wrote:
Blocking outbound TCP SYN packets on port 25 from non-servers is considered a BEST PRACTICE
...
The SMTP submission port (TCP 587) is authenticated and should generally not be blocked.
Email Submission Operations: Access and Accountability Requirements <http://www.ietf.org/rfc/rfc5068.txt> IETF BCPIt does not explicitly support blocking outbound port 25, since that's controversial, but it /does/ require permitting outbound port 587.
d/
Regards, Bill Herrin
-- Dave Crocker Brandenburg InternetWorking bbiw.net
Current thread:
- RE: Outgoing SMTP Servers, (continued)
- RE: Outgoing SMTP Servers up (Oct 26)
- Re: Outgoing SMTP Servers Mikael Abrahamsson (Oct 24)
- Re: Outgoing SMTP Servers Owen DeLong (Oct 25)
- Re: Outgoing SMTP Servers Aftab Siddiqui (Oct 25)
- Re: Outgoing SMTP Servers Scott Howard (Oct 26)
- Re: Outgoing SMTP Servers Jeff Kell (Oct 26)
- Re: Outgoing SMTP Servers Owen DeLong (Oct 25)
- Re: Outgoing SMTP Servers Valdis . Kletnieks (Oct 25)
- Re: Outgoing SMTP Servers Owen DeLong (Oct 25)
- Re: Outgoing SMTP Servers Robert Drake (Oct 25)
- Re: Outgoing SMTP Servers Dave CROCKER (Oct 25)
- Re: Outgoing SMTP Servers Owen DeLong (Oct 25)
- Re: Outgoing SMTP Servers Jeroen Massar (Oct 25)
- Re: Outgoing SMTP Servers Owen DeLong (Oct 25)
- Re: Outgoing SMTP Servers Jeroen Massar (Oct 25)
- Re: Outgoing SMTP Servers Owen DeLong (Oct 25)
- Re: Outgoing SMTP Servers Ricky Beam (Oct 25)
- Re: Outgoing SMTP Servers Alex Harrowell (Oct 25)
- Re: Outgoing SMTP Servers Robert Bonomi (Oct 25)
- Re: Outgoing SMTP Servers Mike Jones (Oct 25)
- Re: Outgoing SMTP Servers Owen DeLong (Oct 25)