Facebook
Last.fm
LinkedIn
Twitter
What I’ve Been Up To Lately
- @OfficialBFBC2: Worst game ever. $90 so I could spend 90% of my time waiting for Bad Company 2 to work. Your network sucks. 5 days ago
- @blinksale: any ETA on some uptime? 2 weeks ago
- PepsiMax + ginkgo = psychological equivalent of a supernova. I give it about 90 minutes before I crash hard. I swear it's holiday time soon. 2010-01-19
- PepsiMax + gingko = psychological equivalent of a supernova. I give it about 90 minutes before I crash hard. I swear it's holiday time soon. 2010-01-19
- If you haven't seen Avatar in 3D yet, you might wanna get on top of that... staggeringly awesome. 2010-01-11
- More updates...
Powered by Twitter Tools
04/01/09
Does your ISP block port 25 (SMTP)?
If you’re like me and are fortunate enough to have your own external SMTP server (which is just about anyone with dedicated or VPS web hosting) here’s a simple but really neat trick….. configure your SMTP service (exim, postfix, et al) to listen on port 587 as well as port 25….. according to the IETF, port 587 is officially reserved for SMTP anyway! Most ISPs cruel enough to block port 25 probably won’t block port 587. And hey, if they do, use a different port…. 26, 8025, 8587, just make sure it’s not something used by another service.
The other side of the equation is your mail client….. alter your SMTP settings and change the port to the new one you specified in your MTA config. It’s possible (I’ve not tested it) that using SSL or TLS may yield positive results too…. I’m not sure if this particular nameless ISP (run by a monopolistic behemoth telco in Australia, hint hint) blocks secure SMTP or not, but I might give it a try and swing an update to this post with my results.
Tags: infrastructure, linux, networking, troubleshooting