Courier 993 connection closed problems

Heeter · 07-23-2015, 06:45 PM

Hi all,

I am currently running a 14.04 LAMP with postfix and courier. This setup has been working flawlessly since I built it when 14.04 came out, other than server updates, I haven't changed anything in the configuration since building the server.

But, alas, I started having issues with my Android device using K9 mail last Friday. It wasn't connecting to the server and retrieving any mail.

This is the result when I run telnet:

Code:

root@server1:/home/adminpc# telnet localhost 993
Trying 127.0.0.1...
Connected to localhost.localdomain.
Escape character is '^]'.
Connection closed by foreign host.
root@server1:/home/adminpc#

And this is the result when I run opensslclient:

Code:

root@server1:/home/adminpc# openssl s_client -connect localhost:993
CONNECTED(00000003)
write:errno=104
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 0 bytes and written 295 bytes
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
---
root@server1:/home/adminpc#

I have deleted the "/etc/courier/imapd.pem" & the "/usr/lib/courier/imapd.pem" files and recreated the keys a few times already:

Code:

root@server1:/home/adminpc# mkimapdcert
/usr/lib/courier/imapd.pem already exists.
root@server1:/home/adminpc#

I restarted courier imap a few times as well

Code:

root@server1:/home/adminpc# service courier-imap restart
 * Stopping Courier IMAP server imapd                                    [ OK ] 
 * Starting Courier IMAP server imapd                                    [ OK ] 
root@server1:/home/adminpc# service courier-imap-ssl restart
 * Stopping Courier IMAP-SSL server imapd-ssl                            [ OK ] 
 * Starting Courier IMAP-SSL server imapd-ssl                            [ OK ] 
root@server1:/home/adminpc#

I also tried uninstalling/reinstalling/reconfiguring courier:

Code:

root@server1:/home/adminpc# apt-get remove courier-authdaemon 
courier-pop courier-pop-ssl courier-imap courier-imap-ssl

but the connection to 993 is always closed (refused)

I am at a loss right now,

Any help would be greatly appreciated,

Regards

Heeter

DarkWolf113440 · 08-23-2015, 01:38 AM

Greetings, Heeter. I'm not too familiar with imap and email servers in general, but if I were having this problem the first thing I'd do is to check your firewall configuration (I assume you have verified the LAMP config) on the LAMP server. It's conceivable that the latest update may have silently modified your firewall settings of maybe reset the firewall to automaticly start on boot if you had previously disabled it. If that checks out and your problem is still not resolved, I would suggest from another Linux box on your LAN use nmap to scan your LAMP server and run Wireshark to capture the raw packets when you attempt to connect with your Android device. An analysis of the results of these two things may yield a clue as to the cause of the problem.

Best wishes with that.