How To Relay Email On A Postfix Server

https://www.howtoforge.com/how-to-relay-email-on-a-postfix-server
https://www.linode.com/docs/email/postfix/postfix-smtp-debian7

1. Prerequisites

I assume that you already have set up a working postfix server and that you have an email account at your ISP which you can access. So you will need to have a login for your IPS's email account.

2. Edit the postfix config

First you need to edit your postfix config...

nano /etc/postfix/main.cf

... and add the following code at the end of your config:

smtp_sasl_auth_enable = yes
smtp_sasl_security_options = noanonymous
smtp_sasl_password_maps = hash:/etc/postfix/saslpasswd
smtp_always_send_ehlo = yes
relayhost = smtp.yourisp.com

smtpd_use_tls=yes
smtp_always_send_ehlo = yes
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
smtp_sasl_tls_security_options = noanonymous
smtp_tls_security_level = encrypt
#smtp_generic_maps = hash:/etc/postfix/generic
smtp_tls_CAfile = /etc/ssl/certs/ca-certificates.crt

mydestination = $myhostname, SMTP, localhost.localdomain, , localhost
relayhost = [smtp.office365.com]:587
mynetworks = 20.10.1.127/32 127.0.0.0/8 20.10.1.6/32 192.168.20.0/24 [::ffff:127.0.0.0]/104 [::1]/128

Of course replace smtp.yourisp.com with the actual smtp server of your ISP. Also SASL must be working. If you followed the perfect howtos for setting up a server as provided by Falko then you don't have to worry about it. Then save and close the file.

If your ISP requires you to use a special port for sending email, then use a line like this instead:

relayhost = [smtp.yourisp.com]:PORT

In one of the cases that I have used this, I had to enter this:

relayhost = [smtpauth.bluewin.ch]:587

3. Edit /etc/postfix/saslpasswd

After having extended the postfix config you'll still need to add the credentials to the /etc/postfix/saslpasswd file, so that you can authorize yourself at your ISP.

nano /etc/postfix/saslpasswd

and then add this:

smtp.yourisp.com     yourlogin:yourpassword

[smtp.office365.com]:587 delivery@gdeasia.com:password

Of course replace yourlogin / yourpassword with the actual username and password provided by your ISP. You don't need to add the port there.

4. Hash /etc/postfix/saslpasswd

Before postfix can use that file, it needs to be hashed by postmap:

postmap /etc/postfix/saslpasswd

5. Restart postfix

Finally you need to restart postfix to use the new config:

/etc/init.d/postfix restart

Apache的Order Allow Deny心得

http://www.fwolf.com/blog/post/191

今天又被这两个参数小小的耍了一把，痛下决心整理一下，免得再被耽误时间。

Allow和Deny可以用于apache的conf文件或者.htaccess文件中（配合Directory, Location, Files等），用来控制目录和文件的访问授权。

所以，最常用的是：

Order Deny,Allow Allow from All

注意“Deny,Allow”中间只有一个逗号，也只能有一个逗号，有空格都会出错；单词的大小写不限。上面设定的含义是先设定“先检查禁止设定，没有禁止的全部允许”，而第二句没有Deny，也就是没有禁止访问的设定，直接就是允许所有访问了。这个主要是用来确保或者覆盖上级目录的设置，开放所有内容的访问权。

按照上面的解释，下面的设定是无条件禁止访问：

Order Allow,Deny Deny from All

如果要禁止部分内容的访问，其他的全部开放：

Order Deny,Allow Deny from ip1 ip2

或者

Order Allow,Deny Allow from all Deny from ip1 ip2

apache会按照order决定最后使用哪一条规则，比如上面的第二种方式，虽然第二句allow允许了访问，但由于在order中allow不是最后规则，因此还需要看有没有deny规则，于是到了第三句，符合ip1和ip2的访问就被禁止了。注意，order决定的“最后”规则非常重要，下面是两个错误的例子和改正方式：

Order Deny,Allow Allow from all Deny from domain.org

错误：想禁止来自domain.org的访问，但是deny不是最后规则，apache在处理到第二句allow的时候就已经匹配成功，根本就不会去看第三句。 解决方法：Order Allow,Deny，后面两句不动，即可。

Order Allow,Deny Allow from ip1 Deny from all

错误：想只允许来自ip1的访问，但是，虽然第二句中设定了allow规则，由于order中deny在后，所以会以第三句deny为准，而第三句的范围中又明显包含了ip1（all include ip1），所以所有的访问都被禁止了。 解决方法一：直接去掉第三句。 解决方法二：

Order Deny,Allow Deny from all Allow from ip1