Problems with sending emails to external domains

[Tom8912]

Hi I am currently an intern doing C# windows form and my company uses CPanel for their email. I have problems sending to external domains such as gmail.com and yahoo.com using the 2 external email ports that are given(25 and 465) I tried using port 587 and it is the only port that managed to send to external domains. I have tested port 25 and it manage to send to internal domains only. Therefore i came to a conclusion that it is related to the settings of the email created in CPanel. I would like to ask are there any advice on what is needed to change to enable the email to be able to send out? Thanks in advance

 

[cPanelMichael]

Hello,

If there are no firewall rules blocking outgoing connections over those ports, then check to see if your provider, or the data center, is blocking outgoing connections over those ports. Data centers/hosting providers will sometimes block outgoing connections over those ports as a SPAM prevention technique.

Thank you.