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So port 25 in the GFW is open for outbound connections? My mailserver spam-log tells me that much every other second. I wonder what weight Spammers had in the

by lolc 10y ago

So port 25 in the GFW is open for outbound connections? My mailserver spam-log tells me that much every other second. I wonder what weight Spammers had in the decision to allow port 25. Though when I think about it, spammers are probably a negligible faction compared to the businesses that would shut down if they couldn't communicate with international clients on Gmail anymore. It would be interesting, as other commenters already remarked, to see what STARTTLS does to the connection.

TorKlingberg 10y ago
The GFW is mostly a blacklist. Unless your site (or your hosting) is on the list, it will work fine from China. It also detects some keywords.
- Iv 10y ago
  It is a dynamic blacklist. It also uses pattern matching and machine learning to detect some undesired behaviors. It will not cut out SSH connections but will recognize the traffic shape of HTTP traffic over it.