Mail Authentication Q & A:
- Why do we need to change from port 25 to port 587 (or 465)?
- Historically, port 25 was used for both server-to-server and end-user-to-server email transfers. But the idea of allowing any virus on any desktop computer anywhere in the world to connect to any email server anywhere in the world is decreasingly popular. A large and growing number of ISPs block outbound email connections in order to stop spam zombies on their network. A new standard is required. Port 25 may work for you on your ISP today, but the time may come when it is blocked without warning. It is best to switch now.
Port 587 is the Internet standard port for email submission.
Port 465 is an earlier, nonstandard port first used by Netscape for email submission over SSL. At this writing, Outlook Express still requires use of port 465; it will not work with port 587.
- My home computer is currently configured to use my ISP's email relay (such as smtp.sympatico.ca). Do I need to change anything?
- At this time, nothing that UofT is doing will impact your ability to use third party email relay servers. However, emerging standards such as Sender Policy Framework (SPF) may lead others to consider email sent through non-UTORmail servers as potential forgeries. To guarantee email delivery, you should consider changing to the authenticated relay.
- I have been using postofficeNN.utcc happily since 1998. Why is this change necessary now?
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- Why are there two ports ?
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- How can I get Microsoft Outlook to use port 587?
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- Can I make Microsoft Outlook Express use port 587?
- Yes -- Apply the following update from Microsoft KB933612
