Change SMTP 220 Responce


#1

I would like to change the SMTP 220 Response. Currently I am receiving “Hi, I’m a Mail-in-a-Box (Ubuntu/Postfix; see https://mailinabox.email/ “. Can anyone help me customize this response?


#2

This would not be a supported change, however this is done in Postfix I believe:
Backup the configuration before editing.

/etc/postfix/main.cf

...
smtpd_banner = This is a greeting / banner.
...

Variable for the hostname is $myhostname.if you need to use a variable in that string.

This will be overwritten with every update.


#3

I will try it. Thank you for your quick response!


#4

Actually, it may improve security, as broadcasting that the server is running mail-in-a-box gives a potential attacker the advantage of knowing the security policies and server configurations, since Mail-in-a-Box has a standard configuration.

I forgot who/what the theory is called where it is a security consideration where or not the protocol or system is known, because an unknown system/protocol is more secure, as attackers are at a disadvantage at approaching an unknown/unfamiliar system. If only I wrote it down…


#5

A simple scan of port 80 on this server already describes it’s MIAB. So changing the banner for security is moot.


#6

Well, if you change all the banners/responses to NOT include MIAB, then there would be an improvement of security.


#7

Security by Obscurity


#8

which some argue is no security at all …