Mailserver with dynamic IP

[minjaverde]

Hi all,

i would just like to share with you how i solved the Problem running a
MailServer with a dynamic IP-Adress. I spend a lot of time to figure this
things out, so i hope some of you can use this to save some time.

Problem :
Some MailServer (for example gmx.net) do not accept Mails from Mail Server with a dynamic IP Adresse.

Resoultion in my case :
I made the following entrys in main.cf :
1 Step
*relayhost = mail.myexternalhostingprovider.ch # replace with your external Mail provider
*smtp_sasl_auth_enable = yes
*smtp_sasl_security_options = noanonymous
*smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd

2 Step
*create /etc/postfix/sasl_passwd or just add the following informations to the sasl_passwd. :
mail.myexternalhostingprovider.ch emailadres@myexternalhostingprovider.ch:PASSWORD
*launch postmap /etc/postfix/sasl_passwd
*restart or reload postfix

After this modifications your Mails will be send allways to
mail.myexternalhostingprovider.ch and will be authenticated with your user emailadres@myexternalhostingprovider.ch and your password PASSWORD.

If it works you will find a message like this in your logfiles (/var/log/syslog or /var/log/mail.info) :

Quote: Jun 01 16:31:04 yourhostname postfix/smtp[15931]: 9637D2F805E: to=<my-mother@gmx.ch>, relay=mail.myexternalhostingprovider.ch[*.*.*.*]:25, delay=0.43, delays=0.05/0.01/0.14/0.24, dsn=2.0.0, status=sent (250 2.0.0 m5HEVhvN020286 Message accepted for delivery)

Second Problem :
May the following Problem only exists on my server, because i just crashed a little bit my postfix configuration, but after this modifications i had the Problem that my server didn't accept any Mails. He always tried to find a local User an tryed to deliver the Mails localy and not to my virtiual Mailboxes. The following Error Message appered in the Logfile :

Quote:Jun 17 13:22:37 yourhostname postfix/qmgr[24444]: D79AB2F805C: from=<christian@mycompanyprovider.com>, size=8904, nrcpt=1 (queue active)
Jun 17 13:22:37 yourhostname postfix/local[24449]: D79AB2F805C: to=<christian@yourhostname.ch>, relay=local, delay=6.8, delays=6.8/0/0/0.01, dsn=5.1.1, status=bounced (unknown user: "christian")

or by sending to a viritual domain :

Quote: Jun 17 15:55:44 yourhostname postfix/smtpd[15251]: connect from mail108.mycompanyprovider.ch[*.*.*.*]
Jun 17 15:55:44 yourhostname postfix/smtpd[15251]: NOQUEUE: reject: RCPT from mail108.mycompanyprovider.ch[*.*.*.*]: 554 5.7.1 <viritual-user@viritual-domain.com>: Relay access denied; from=<christian@mycompanyprovider.com> to=<viritual-user@viritual-domain.com> proto=ESMTP helo=<mail108.mycompanyprovider.ch>

after hours of searching trough the internet and reading the postfix handbook, i found a hint that if you enter a relay_host you have to add your domains to the /etc/postfix/domains (or under ispcp /etc/postfix/ispcp/domains).

Resoultion in my case :
*i add my 3 domains into the domains file with the following Syntax :

Quote: mydomain1.com OK
mydomain2.net OK
mydomain3.net OK

*bulding the .db file with postmap /etc/postfix/ispcp/domains
*restartet postfix again


... and after all this i could send Mails to any Mailserver an Receivend any Mails for mydomains on my webserver :)

hope this helps anybody with a equal Problem, hope this makes sens to you if not, let me hear your Feedback
thx minja

[rbtux]

second problem is a configuration issue of yours. For the first one you could have saved a lot of time if you had read the documentation ;-)
http://www.isp-control.net/documentation...mtp_server

[minjaverde]

i know after solving problems you will always find a good tutorial :-)
Important is to read the right documentation :-) or searching with the right words.

maybe a hint should be made to this How To. This How To explains how to solve this Problem but doesn't match this specified Problem to the Soultion (maybe this exists already and i was to blind to find that too :-)). The doing was the smaller Part.

anyway i know i am not perfect ;-)