[X-Newbies] Mail.app

[Paul Baily]

Hi Jane,

On 02/02/2005, at 2:10 PM, Jane wrote:

> What is the problem with the can't send on port 25 error? Is the 
> server down or what?

Some ISPs block outbound port 25 traffic in an effort to reduce the 
amount of spam & viruses being sent from their networks, e.g. 
infected/compromised Windows PCs, or hit and run spam passes from 
residential broadband connections.

Debate persists as to whether this is a Good Thing or just punishes the 
innocent, but there's quite a good explanation here:

<http://www.postcastserver.com/help/Port_25_Blocking.aspx>

It appears Comcast (I'm guessing this is the ISP you're currently 
using) is one such ISP.

Some mail services offer ways around this by using a higher arbitrary 
port number that isn't blocked, e.g. with my webhost (Pair) I'm able to 
send mail from any location whether a port 25 block is in effect or 
not, because they also accept mail (on a POP before SMTP basis) on port 
2525. I'm pretty sure mac.com has (or had - it's been a while) a 
similar method.

HTH, and cheers,

Paul.