Email Problems: Gmail and PostFix Solutions

[edisoninfo]

It appears that Time Warner has now uploaded their entire list of dynamic IP's to a spam list of some sort. So almost all of the outbound emails are being rejected. The linux boxes that I use Postfix on are very easily configured to send outbound through TW's email server masquarading as a valid domain. But, the piaf boxes all default to sendmail and I just can not get the sendmail.cf, etc/hosts, hostname, etc. configured right to get email out. I tried switching them to Postfix but did not succeed there either. Any pointers?

 

[wardmundy]

Our strongest recommendation is to implement the Gmail Solution with SendMail. You'll never have to worry about outbound email again.

 

[krzykat]

Our strongest recommendation is to implement the Gmail Solution with SendMail. You'll never have to worry about outbound email again.

I concur with this 110% !!! In addition, you don't have to worry about your inbound e-mail not getting in if your internet ever goes down.

 

[TheShniz]

Seeing how sendmail is arguably the most popular mail server there is... one of my long-standing wishes is that someone could really enlighten everyone. I get sendmail to work everytime, and don't ever want to use Google for anything... just don't ask me how.

My notes on PostFix (not tested):

# Uninstall Sendmail
rpm -e --nodeps sendmail (uninstalls sendmail)

# Install Postfix
yum -y install postfix
nano /etc/postfix/main.cf
Add line relayhost = smtp.isp.com (e.g. smtp.comcast.net)
reboot

Another related question I wish I knew more of, was how to redirect to different ports (e.g. 587) and add authentication. I've come across requests for these, but have always managed to work a way around them. I just wish I knew more here...

 

[edisoninfo]

To change ports add a :587 to the end of the hostname. Also, if you add brackets like [hostname] turns off MX lookups.

ie.
relayhost = [smtp.isp.com]:587

For authentication are you referring to outbound? Like logging into your isp with your user/pwd to send a message? Most isp's seem to be requiring that now. It is a little more difficult but not bad. The hardest part is making sure you have a version of postfix installed that supports sasl. Run postconf -a and postconf -A and you should see Cyrus listed. If not, you do not have it.

Add these lines to the postfix main.cf file

smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasldb
smtp_sasl_security_options = noanonymous

create the /etc/postfix/sasldb file and put the smtp hostname you used above, then a tab, then the username and password to log into the isp seperated by a :
ie.
smtp.isp.com <tab goes here> username : password (no spaces. It kept showing a smiley face)


Then run the command postmap sasldb and it should create a hashed version of the file called sasldb.db

Restart postfix and wha-la....

Run the command tail -f /var/log/maillog and watch for errors. Ctrl-C will get you out of it.