TMNet's Streamyx, as part of their antiflooding attempts of their service implements the blocking of port 25 which is commonly used for sending emails using SMTP for. As a streamyx user (non corporate/non fixed IP user), you may find this a nuisance especially if you use your office corporate email to send and receive emails.
So, what are our options here?
1. Use Streamyx's SMTP.
Use the smtp server smtp.streamyx.com. Make sure to provide authentication in the form of firstname.lastname@example.org and provide your streamyx broadband password. Be aware that the default streamyx password tmnet123 should be changed immediate at https://tmbill.tm.net.my/SelfCare/Maintenance/selfcareLogin.jsp then use another complex password. When doing this, it will affect your streamyx login (when dialing into streamyx on your PC or router) as well as your email facilities and online billing facilities.
2. If you can, use SMTP on another port, e.g. port 20025. Most SMTP server is capable of adding a new port to an existing IP address or another IP address. Open up your corporate firewall for that port and change the port settings of your corporate email to the port you've specified in your corporate email server's SMTP service.
3. Use VPN
Anything inside the VPN tunnel cannot be "seen" by filters like TMNet's packet filters
4. Use webmail - no explaination needed here rite :P
5. Change to different ISP (yea, like we've got heaps of choices, sigh)