Bug 3495 - IPv6 specific name resolution Error
Summary: IPv6 specific name resolution Error
Alias: None
Product: Claws Mail (Windows)
Classification: Unclassified
Component: default (show other bugs)
Version: 3.12.0
Hardware: PC Windows 8
: P3 major
Assignee: users
Depends on:
Reported: 2015-08-13 08:26 CEST by Dravion Smith
Modified: 2015-09-10 22:56 CEST (History)
1 user (show)

See Also:


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Description Dravion Smith 2015-08-13 08:26:58 CEST
Iam the postmaster of a own Postfix/Dovecot POP3+IMAP Installation and there is a major problem in the Claws Win32 Version when it comes to Name Resolution of IPv6 Addresses and even connectivity Problems if you use plain IPv6 Addresses
as Hostnames. On the Postfix Serverside i see no incomning Connection and
Claws Reports the Error: "Unknown Host". But the host is avaiable via ping -6 and tracert, i can also connect manually via telnet 25 and telnet 110 (pop)
and just send a plaintext email. Mutt and other Clients playing well with IPv6.

Note: If i provide Claws a IPv4 IP-Address, evertything works as expected.
Comment 1 Dravion Smith 2015-08-13 08:31:53 CEST
IPv6, Windows (32-Bit), general connectivity Problem, but IPv4 Connections works fine.Other IPv6 capable E-Mail-Clients like MS-Offoce 2013 or Thunderbird
38.1.0 (win32) is working fine on IPv6 on Windows.
Comment 2 users 2015-08-20 08:29:04 CEST
Changes related to this bug have been committed.
Please check latest Git and update the bug accordingly.
You can also get the patch from:

++ ChangeLog	2015-08-20 08:29:02.732280727 +0200
Merge: d4741c3 8f4236e
Author: Colin Leroy <colin@colino.net>
Date:   Thu Aug 20 08:29:02 2015 +0200

    Merge branch 'master' of file:///home/git/claws

Author: Andrej Kacian <ticho@claws-mail.org>
Date:   Wed Oct 1 22:00:06 2014 +0200

    Use getaddrinfo() instead of gethostbyname() in socket.c.
    Closes bug #3253, as we're trying all resolved addresses.
    This should also make IPv6 work on Windows, bug #3495.
Comment 3 Andrej Kacian 2015-09-10 22:56:49 CEST
I have just fixed this in git. IPv6, both using hostnames and plain IP addresses, will be working in next release.