[RndTbl] Shaw now blocking SMTP port 25

Kevin McGregor 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
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