How to rewrite outgoing email address in sendmail

We can edit the file below to rewrite outgoing email address.

/etc/mail/genericstable


Add the line below

youraccount [email protected]


regenerate the hash file

makemap -r hash genericstable.db < genericstable



You can also edit /etc/mail/aliases for local accout


Alias to your alias account

youraccount   youaliasaccount


Or alias to your device

youraccount   /dev/yourdevice


Remeber use newaliases to update the hash file

How to disable IPv6 in Postfix

If you send mail to gmail server without correct PTR records, you'll get the reject message below.

"message does not meet IPv6 sending guidelines regarding PTR records 550-5.7.1"

You may update PTR record, or disable IPv6 if you don't need it.


Edit main.cf

Update the value with ipv4 in this line "inet_protocols = all"

inet_protocols = ipv4



You might get another message  "config variable inet_interfaces: host not found: [::1]"

Update the value with 127.0.0.1 in this line "inet_interfaces = 127.0.0.1, [::1]" will solve the problem.

How to rewrite outgoing email address

When we call mail function by php on Linux , we can use postfix.

However, the sender will be always apache or www-data, since the system use default web user name as the sender name.

We can rewrite email of the sender by steps below.

Step 1

Check configuration in php.ini

[mail function]
; For Win32 only.
SMTP = localhost

; For Win32 only.
;sendmail_from = ***@yourdomain.com

; For Unix only. You may supply arguments as well (default: "sendmail -t -i").
;sendmail_path =\r



Step 2

Edit main.cf for postfix

vi /etc/postfix/main.cf



Step 3

Specify the generic map file in main.cf

smtp_generic_maps = hash:/etc/postfix/generic



Step 4

Edit generic file

vi /etc/postfix/generic


Step 5

Specify the mapping address

[email protected]   [email protected]


Step 6

Create postfix db hash file

postmap /etc/postfix/generic


Step 7

Restart postfix

/etc/init.d/postfix restart



You will need use sender_canonical_maps = hash:/etc/postfix/canonical instead if your postfix is earlier version.