If you are not familiar with Port 25, Port 25 is the virtual pathway that most e-mail use to route the outgoing message to a local server. If this port is block most probably you will not able to send any email coming from your email client such as outlook express unless your ISP provide a new smtp and port # to use.
Now back to the topic, just recently I noticed that I can no longer send email via OE with the use of my registered domain so I was thinking that the problem is on my hosting. I emailed the tech support several times but they keep on saying that there’s no problem on their side so I stop. though the tech support is very helpful and suggested to test if my ISP is blocking the port 25.
This is the error message that I’m receiving when sending email using my Outlook Express.
The connection to the server has failed. Account: ‘mail.testdomain.com’,
Server: ‘mail.testdomain.com’, Protocol: SMTP, Port: 25, Secure(SSL): No,
Socket Error: 10051, Error Number: 0x800CCC0E
I had several testing(disabling my av, turn-off my firewall, using telnet) and found out that the “SALARIN” is my ISP. Jologs talaga!!! Those %#$! did not even notify us customers before blocking the port.
So here’s what I got to resolve the issue… Don’t bother to call PLDT, just update your current setting with the following information below.
Outgoing mail server SMTP: smtpdsl4.pldtdsl.net
My outgoing server (SMTP) requires authentication: Uncheck it
USE Port: 587
Hope this helps ^______^