Relayhost?

[wr19026]

Hi,

So now I have a working system that I can access from inside my own network as well :) Being a total noob it took me long enough to get here!

Now I need some advise:
Outgoing mail is not a problem but incoming mail is. I just don't receive anything. So I looked up all possible solutions and came to the conclusion that it had to have something to do with DNS.

Turns out my ISP is blocking port 25. Which is fine as long as I can receive mail. Which I currently can't. They recommend that I set up mail DNS at NetworkSolutions where I have registered my domainname as follows:
10 server.mydomain.dom
20 mailrelay.myisp.dom

Now I was thinking, there is a field called "relayhost" in main.cf for Postfix as well so perhaps I should use that instead.

Any suggestions (and explanations why) as to which solution would be better?

My ISP actually wants me to use the "smarthost" option for Postfix. How would that impact my setup (if at all)?

Thanks in advance.

[till]

The relayhost in postfix is for outgoing mail, not incoming.

I'am not familar with the smarthost option in postfix, but i think you can not host a real server when port 25 is blocked.

[wr19026]

This is what my main.cf looks like after I reconfigured Postfix to Internet with smarthost:

root@server:~# more /etc/postfix/main.cf
# See /usr/share/postfix/main.cf.dist for a commented, more complete version

smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no

# appending .domain is the MUA's job.
append_dot_mydomain = no

# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h

myhostname = server.mydomain.dom
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
#mydestination = mydomain.dom, server.mydomain.dom, mail.server.mydomain.dom, localhost.mydomain.dom, localhost
relayhost = mailrelay.direct-adsl.nl
mynetworks = 127.0.0.0/8
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
smtpd_sasl_local_domain =
smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
broken_sasl_auth_clients = yes
smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,reject _unauth_destination
smtpd_tls_auth_only = no
smtp_use_tls = yes
smtpd_use_tls = yes
smtp_tls_note_starttls_offer = yes
smtpd_tls_key_file = /etc/postfix/ssl/smtpd.key
smtpd_tls_cert_file = /etc/postfix/ssl/smtpd.crt
smtpd_tls_CAfile = /etc/postfix/ssl/cacert.pem
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
smtpd_tls_session_cache_timeout = 3600s
tls_random_source = dev:/dev/urandom
home_mailbox = Maildir/
mailbox_command =

virtual_maps = hash:/etc/postfix/virtusertable

mydestination = /etc/postfix/local-host-names


So what it definitely does is replace mydestination by /etc/postfix/local-host-names

Do you see any risks associated with that?

[falko]

virtual_maps = hash:/etc/postfix/virtusertable

mydestination = /etc/postfix/local-host-names


So what it definitely does is replace mydestination by /etc/postfix/local-host-names

These last two lines
virtual_maps = hash:/etc/postfix/virtusertable

mydestination = /etc/postfix/local-host-names were added to /etc/postfix/main.cf by the ISPConfig installer!

[wr19026]

These last two lines
virtual_maps = hash:/etc/postfix/virtusertable

mydestination = /etc/postfix/local-host-names were added to /etc/postfix/main.cf by the ISPConfig installer!

So it seems that changing the configuration for Postfix to Internet with Smarthost (or whatever the right option is) did not really change my main.cf and therefore should not have an enormous impact on how ISPConfig works. Or is that too easy :)

[falko]

As far as I can see, your main.cf looks like any other main.cf on Debian and Ubuntu systems that have been set up using the "Perfect Setups". I can't see anything about Smarthost.

[wr19026]

As far as I can see, your main.cf looks like any other main.cf on Debian and Ubuntu systems that have been set up using the "Perfect Setups". I can't see anything about Smarthost.

I think that what the smarthost option does is fill the "relayhost" value.

[till]

If i read your posts correctly, you have problems with incoming mail, not outgoing?

The relayhost tells postfix to send emails trough another server and not directly. This can only solve problems with outgoing emails and blacklisting of dynamic IP addresses.

[wr19026]

If i read your posts correctly, you have problems with incoming mail, not outgoing?

The relayhost tells postfix to send emails trough another server and not directly. This can only solve problems with outgoing emails and blacklisting of dynamic IP addresses.

The funny thing is though that since I changed my config to Internet w/smarthost my outgoing mail is working. So the issue is solved; at least for me. But I think that with more and more ISPs using relay hosts to avoid blacklisting this might be something that will pop up more and more in the future.