[RndTbl] Shaw now blocking SMTP port 25
kmcgregor at shaw.ca
Wed May 23 13:14:07 CDT 2007
It wasn't clear from my message, but the part after "does:" was clipped from a Google Mail support page, including the bits in parentheses (for the record). Aside from that, it looks like you agree with me! :) I must learn to be less terse.
----- Original Message -----
From: "Gilbert E. Detillieux" <gedetil at cs.umanitoba.ca>
Date: Wednesday, May 23, 2007 12:16 pm
Subject: Re: [RndTbl] Shaw now blocking SMTP port 25
> On 2007-05-23 11:41, Kevin McGregor wrote:
> > Well... yeah. Note that you can still do outbound SMTP if the
> > destination SMTP server supports SSL/STARTTLS, such as
> smtp.gmail.com does:
> > Outgoing Mail (SMTP) Server - requires TLS: smtp.gmail.com
> (use authentication)
> > Use Authentication: Yes
> > Use STARTTLS: Yes (some clients call this SSL)
> > Port: 465 or 587
> Actually, there is a difference between TLS (or STARTTLS) and SSL. With
> SSL, encryption is enabled (or at least negotiated) right from the
> initial connection. An alternative port number is typically used for
> this reason. With TLS, the connection starts off in plain text, and
> encryption is (optionally) negotiated later, provided both sides support
> it. An alternative port number is usually not necessary for this.
> Of course, if the whole point is to get around blocking of port 25, then
> an alternative port will be required, whether TLS or SSL is used.
> > So, it's not ideal as this won't be a solution which can be used by
> > everyone affected, but at least it's something.
> The problem with this is there isn't a clear standard for alternative
> ports for SMTP. So, you need to find out if your particular mail
> service supports it, and if so, on what port (and with what encryption
> options). Of course, if a standard (even de facto) were to emerge, it
> might just shift the spam problem to the other port, unless it only
> supports authenticated connections (which, I believe, required TLS
> support, not just SSL).
> Gilbert E. Detillieux E-mail: <gedetil at muug.mb.ca>
> Manitoba UNIX User Group Web: http://www.muug.mb.ca/
> PO Box 130 St-Boniface Phone: (204)474-8161
> Winnipeg MB CANADA R2H 3B4 Fax: (204)474-7609
> Roundtable mailing list
> Roundtable at muug.mb.ca
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