Setting Up Postfix (Linux)

With Postfix, you can manage your 1&1 IONOS email accounts securely under Linux.


Please make sure that the following modules are installed on your computer in addition to Postfix in the case of SuSE Linux:


Postfix 1.x
  • postfix-tls
  • libsasl-modules-plain
  • sasl-bin
  • ibsasl-digestmd5-plain
For Postfix 2 you only need the following packages:
  • cyrus-sasl
  • postfix
Step 1

Edit the configuration file /etc/postfix/ as follows:


relayhost =
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps =  hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous 
smtp_use_tls = yes
Step 2

If it does not already exist, create the file /etc/postfix/sasl_passwd and enter the access data for your mailbox as follows:


Please replace our example information "" and "mypass" with the 1&1 IONOS email address and the corresponding email password.

Step 3

Now you should change the access rights so that only "root" can view and edit the file. You do this with the command

chmod 600 /etc/postfix/sasl_passwd

The permissions should now look like this:

-rw------ root root
Step 4

Convert the file to the.db format used by Postfix:

postmap /etc/postfix/sasl_passwd

and restart Postfix:

/etc/init.d/postfix reload