Outlook cannot connect to your mail server ?
When setting up Outlook, or after ISP network changes, it is a common annoyance to be unable to send/receive email with a message of this type:
"Outlook cannot connect to your outgoing (SMTP) e-mail server. If you continue to receive this message, contact your server administrator or internet service provider (ISP)."
Navigate to your email account settings in Outlook under: Tools > Account settings > highlight your account and click "change" > click "more settings"
Look through all the tabs. Make sure the outgoing/incoming mail servers, your username and password are correct.
Under "Outgoing Server", make sure you check: "My outgoing server (SMTP) requires authentication" and "Use same settings as my incoming mail server"
In the "Advanced" tab:
Select the correct type of encryption, and the correct ports for "Incoming server" (usually 110) and "Outgoing server (SMTP)" - 25 is the default outgoing port, however, many major ISPs block this port to reduce outgoing spam, so if you're not using your ISP for email, it may be blocked and that is probably the culprit. As an alternative, try port 2525, or one of the secure ports below.
Here is a list of the default standard mail ports for your reference:
SMTP - port 25
You can also try scanning the above ports to see which one is open on your mail server using our portscan, and/or you can also contact your ISP to verify whether they are blocking any mail ports, port 25 is the most common one being blocked.