Add configuration for inter-corporate.com eMail provider

[randolf]

A major internet provider is intermittently blocking IPv6 connections, which prevents automatic configuration in Mozilla Thunderbird, Evolution, etc., for more of our clients now that Linux is gaining popularity. We're hoping that inclusion in ISPDB will resolve this problem more easily than wasting any more time in trying to convince the internet provider's technical support to fix their IPv6 issues (we rejected their recommendation to drop IPv6 support).

Thank you.

[babolivier]

Hi, and thanks for your PR!

Just to help me understand your situation a bit better: I can see inter-corporate.com hosts a configuration file at https://autoconfig.inter-corporate.com/mail/config-v1.1.xml. From DNS lookups, I can see that the autoconfig.inter-corporate.com domain has both an AAAA record for IPv6 and an A record for IPv4, and both seem able to serve the configuration file:

$ dig +short -t A autoconfig.inter-corporate.com
65.110.3.188
$ dig +short -t AAAA autoconfig.inter-corporate.com
2605:7c00:1:2:65:110:3:188
$ curl -v -4 https://autoconfig.inter-corporate.com/mail/config-v1.1.xml 2>&1 | grep -i "content-type"
< Content-Type: text/xml
$ curl -v -6 https://autoconfig.inter-corporate.com/mail/config-v1.1.xml 2>&1 | grep -i "content-type"
< Content-Type: text/xml

So what is preventing users from accessing the configuration file over IPv4?

It's also worth noting the same applies to ISPDB: autoconfig.thunderbird.net (which serves configurations from ISPDB) is available over both IPv6 and IPv4. So I'm not entirely sure I understand how adding an ISPDB entry would solve your problem.