Could not open connection to the host, on port 25: connect failed

mail error
SMTP Error

Error Msg : Could not open connection to the host, on port 25: connect failed

What does this mean ?

You web application is not able to reach the SMTP Host using Port 25.

Possible Reasons…

1. If Web Server itself relays the email check for SMTP service under Services and as well as under IIS.

2. If Email Relay server is different make sure your web server is able to reach it (by pinging).

2a. Verify with admin, whether Port 25 is open.

3. Check Firewall (software or firewall server) on your server (to allow outgoing connection)

4. Check firewall (software or firewall server) on Relay server (to accept incoming connection from your server).

5. Check the Virus Scanner on your server. Some scanners like MCAFee / Norton disables mass mailing by default.

If you have come across any other scenario please add it in comments.

5 thoughts on “Could not open connection to the host, on port 25: connect failed

  • October 24, 2009 at 9:10 pm
    Permalink

    All above 5 items are cleared, but still get below message

    Could not open connection to the host, on por
    t 25: Connect failed

    Any ideas?

    Thanks

    CK

    Reply
  • August 25, 2010 at 3:13 am
    Permalink

    could you please explain number one If Web Server itself relays the email check for SMTP service under Services and as well as under IIS.

    Reply

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