[Dovecot] IMAP not working remotely

[Ondřej Bouda]

...and the same applies for Dovecot 2.0.1 and Dovecot 2.0.13.
Am I overlooking something?

Ondrej Bouda



On Fri, 08 Jul 2011 23:44:59 +0200, Ondřej Bouda <xbouda2 at fi.muni.cz>  
wrote:

> Hello,
>
> I am trying to set up Dovecot 2.0.9 on Fedora 14. The problem I would  
> like to ask for resolution is that IMAP is not working when connecting  
> to the server from another network.
>
> More precisely:
> - POP3 is working entirely OK,
> - IMAP is working OK when clients are connecting using local network  
> addresses, like 192.168.0.100,
> - when a client connects from outside, thus using remote IP address, or  
> even from the server itself using the remote IP address of the server,  
> the following happens: the client correctly connects, but the server  
> sends no greeting (neither the configured login_greeting nor the server  
> IMAP capabilities) and does not respond to the commands. In the server  
> log, I get the following record a while after trying to connect (and  
> actually trying to login):
> Jul 08 23:24:16 imap-login: Info: Disconnected: Inactivity (no auth  
> attempts): rip=<remote-server-address>, lip=192.168.0.100
>
> Both routing and firewall are OK. The client really connects to dovecot  
> (hence the log message), as seen from a telnet session:
> Trying a.b.c.d...
> Connected to example.tld (a.b.c.d).
> Escape character is '^]'.
> (and then nothing else)
>
> The most confusing for me is the fact that POP3 is configured quite the  
> same and works fine, as well as IMAP on the local network. I tried to  
> change address in the inet_listener imap configuration, but if a wrong  
> address setting was the cause, the client would not get connected at all.
>
> As I have spent a pretty long time unsuccessfully searching for a cause,  
> I am asking for some help.
>
> Thanks for your time,
> Ondrej Bouda
>
>
>
> dovecot -n output follows:
>
> # 2.0.9: /etc/dovecot/dovecot.conf
> # OS: Linux 2.6.35.11-83.fc14.x86_64 x86_64 Fedora release 14 (Laughlin)  
> ext4
> auth_mechanisms = plain login cram-md5 digest-md5 ntlm
> disable_plaintext_auth = no
> first_valid_gid = 502
> first_valid_uid = 502
> last_valid_gid = 502
> last_valid_uid = 502
> log_path = /var/log/dovecot
> login_greeting = Welcome
> mail_location = maildir:/var/mail/virtual/%d/%n
> passdb {
>    args = scheme=plain username_format=%u /etc/dovecot/passwd
>    driver = passwd-file
> }
> protocols = imap pop3
> service auth {
>    unix_listener /var/spool/postfix/private/auth {
>      group = postfix
>      mode = 0660
>      user = postfix
>    }
>    user = dovecot-auth
> }
> service imap-login {
>    inet_listener imap {
>      address = *
>      port = 143
>    }
> }
> service pop3-login {
>    inet_listener pop3 {
>      address = *
>      port = 110
>    }
> }
> ssl = no
> userdb {
>    args = username_format=%u /etc/dovecot/passwd
>    driver = passwd-file
> }
> protocol pop3 {
>    pop3_client_workarounds = outlook-no-nuls oe-ns-eoh
>    pop3_uidl_format = %08Xu%08Xv
> }