Thanks. That was the problem
Leo
On 4/6/19 10:53 pm, Bill Cole wrote:
On 4 Jun 2019, at 8:23, subscription1 wrote:
telnet on the working server shoews
---
>>> telnet 203.205.219.57 25
Trying 203.205.219.57...
Connected to 203.205.219.57.
Escape character is '^]'.
220 newxmmxsza20.qq.com MX QQ Mail Server.
^]
telnet>
----
On the failing server I get
---------------
>>> telnet 203.205.219.57 25
Trying 203.205.219.57...
------------------
I can ping 203.205.219.57 from both servers
This is a symptom of your network provider blocking port 25 outbound.
That has long been the norm for residential/recreational service and
in recent years it has expanded to the low-end hosting market
(including Amazon and OVH,) where it is now common for hosting
providers to block port 25 outbound by default and either provide an
authenticated relay service (e.g. Amazon SES) or to unblock the port
by customer request. Making the issue more complex, some providers
have implemented port 25 blocking unevenly, so that some of their
customers or networks are unblocked despite the official practice.
