port question

[Tony Alfrey]

David A. Bandel wrote:

> 
>> 3.  The SMTP *client* in (1) sets a port within the TCP/IP protocol packets
>> of the outgoing mail.  If Port 25 is set, it may be rejected by the outgoing
>> SMTP *server*, and never re-sent (relayed).  Correct?
> 
> the smtp client may request a different port, but that would usually
> be because the network the client is on has port 25 blocked at its
> border and the smtp server is beyond the border


I must select Port 587 for the SMTP server settings when I use my e-mail 
client (SMTP client?), otherwise I cannot get my packets to be accepted 
by my SMTP server (earthlink) or allowed for transmission to my SMTP 
server by my isp (comcast).   But you (and other) sources say that Port 
25 is always used for internet e-mail.  Does this mean that the port ID 
in the packets is changed from port 587 to port 25 (or additional port 
25 headers added) by the transmitting SMTP server?



-- 
Tony Alfrey
tonyalfrey at earthlink.net
"I'd Rather Be Sailing"