There are two main causes of email sending problems when attempting to connect to the ICOMEX mail server:
ISP Blocking Port 25
IP Port 25 is the default port for sending email. As a SPAM prevention measure, many Internet Service Providers (ISP's) have adopted the practice of blocking port 25 for accessing any mail server outside of their network. This means that if you are attempting to send email through the ICOMEX mail server while connected through some ISP's networks, then your email client may not connect.
There are two way to resolve this issue:
Simply change your outbound server port to 587, which we make available as an alternative to port 25. This setting is usually found in the Advanced Setting section of many email clients.
Change your outbound server settings to use the ISP's sTMP server. You will need to contact your ISP for this information, or refer to your ISP subscription information. This setting is usually found in the Servers Setting section of many email clients.
ICOMEX employs the use of several of the most reliable 'blacklist' systems to curb the amount of SPAM to comes in to our mail server, and consequently is passed on to you. Blacklists operate by comparing the IP address of a computer attempting to send email through our mail server against a database of addresses that are known to have sent SPAM in the past. Given that there is only a finite number of IP addresses available in the world, ISP recycle IP address for DSL, Cable, and Dial-Up access all the time. Therefore, it is possible, and even likely, that at some point you will get assigned an IP address that someone else has abused in the past.