Outbound SMTP Port 25 Changes
** This affects services located in Hong Kong and Sydney ONLY **
Starting 02/01/2016, SoftLayer will be implementing additional measures to stop malicious internet actors that look to the SoftLayer platform as a resource for them. One of the measures they are implementing is a traffic filter to block outbound TCP port 25, which will prevent your VPS instances from sending direct outbound email.
We ask that you review your systems and applications to determine if they are sending direct outbound email. Once these changes are implemented, your public IP address(es) will cease to have access to send traffic outbound via TCP port 25, and any direct email which is created by your systems will need to route through an SMTP relay (typically TCP port 587 or 465).
We recommend using one of the many SMTP relay services available, such as Mandrill, SendGrid and MailGun. For more information, please visit this link: http://blog.softlayer.com/2015/ongoing-actions-eliminate-spam-hosting
Monday, January 18, 2016