SMTP-server seams tob e down within Postfix

My Debian server is located in a datacenter and the system ports for smtp, ssh, ftp, pop3, http are monitored.
When one of these processes is down, I will receive a sms on my mobile phone.
According my ISPConfig hosting-controlpanel everything is functioning fine.
And I do not have any problems with any of the running processes but …
everytime I receive a message from datacenter that my smtp is down.
Two minutes later or so, I receive a sms again that all running processes are running and that my server is fine. This happens again and again.

I have contacted the company in the datacenter, and they told me that when my smtp-server is not showing the initial greeting within 20 seconds, the monitoring system thinks that my smtp-server is down.

I think it has something to do with a setting within Postfix, I had a look at this problem, but it is not clear to me why this problem occurs.

Can anyone give me advise?

I would be very grateful.

 

Till,
I have setup a telnet connection.
It took 28 seconds to establish the connection,
which is 8 seconds more then the 20 seconds i mentioned before.

Hans

 

Till,
I have setup a telnet connection.
It took 28 seconds to establish the connection,
which is 8 seconds more then the 20 seconds i mentioned before.

To be more precise:

It took me 28 sec. to reach my server from my pc at home to the server in the datacenter.
THe command i used was: telnet <ip-address> 25

On my server itself, it took almost no time.
I used the command: telnet localhost 25

Hans

 

Anything in the mail log?

 

logfile

Falko,

The lines below is a copy of small piece of my /var/log/mail.log file.
As you can see, the first two lines there is a normal behaviour (connect/disconnect).
The next lines look strange to me, but i do not know why this accurs.
I hope you can help me.

Hans

---
Feb 23 07:15:58 server1 postfix/smtpd[4227]: connect from sms-monitor.transip.nl[80.69.67.10]
Feb 23 07:15:58 server1 postfix/smtpd[4227]: disconnect from sms-monitor.transip.nl[80.69.67.10]
Feb 23 07:17:55 server1 courierpop3login: Connection, ip=[::ffff:80.69.67.10]
Feb 23 07:17:55 server1 postfix/smtpd[4269]: unable to get certificate from '/etc/postfix/ssl/smtpd.crt'
Feb 23 07:17:55 server1 postfix/smtpd[4269]: 4269:error:02001002:system library:fopen:No such file or directory:bss_file.c:2$
Feb 23 07:17:55 server1 postfix/smtpd[4269]: 4269:error:20074002:BIO routines:FILE_CTRL:system lib:bss_file.c:280:
Feb 23 07:17:55 server1 postfix/smtpd[4269]: 4269:error:140DC002:SSL routines:SSL_CTX_use_certificate_chain_file:system lib:$
Feb 23 07:17:55 server1 postfix/smtpd[4269]: TLS engine: cannot load RSA cert/key data
Feb 23 07:17:55 server1 postfix/smtpd[4269]: connect from sms-monitor.transip.nl[80.69.67.10]
Feb 23 07:17:55 server1 postfix/smtpd[4269]: disconnect from sms-monitor.transip.nl[80.69.67.10]
---

 

directory contents

Till,

hereby i send you the directory contents of /etc/postfix/ssl
server1:/etc/postfix/ssl# dir
cacert.pem cakey.pem smtpd.csr smtpd.key


Is this ok or do i miss smtpd.crt ? If so, how can i correct the problem?

Hans

 

Run these commands:

Code:

cd /etc/postfix/ssl/
openssl genrsa -des3 -rand /etc/hosts -out smtpd.key 1024
chmod 600 smtpd.key
openssl req -new -key smtpd.key -out smtpd.csr
openssl x509 -req -days 3650 -in smtpd.csr -signkey smtpd.key -out smtpd.crt
openssl rsa -in smtpd.key -out smtpd.key.unencrypted
mv -f smtpd.key.unencrypted smtpd.key
openssl req -new -x509 -extensions v3_ca -keyout cakey.pem -out cacert.pem -days 3650

Then restart Postfix.

 

Falko,
Thank you so much!
It seems to be working now.

Hans