Remove Exim version number

Open the file /etc/exim.conf and find the key smtp_banner, then change that line in this way :


smtp_banner = "${primary_hostname} ESMTP Exim ${version_number} \ 


smtp_banner = "${primary_hostname} ESMTP \

smtp_banner modifies the banner displayed to the client upon connection, but it looks like you want to change what's being put in the Received: header.

For that, you'll want to define received_header_text, probably in /etc/exim4/conf.d/main/02_exim4-config_options. The option isn't in the file by default, but per the documentation the default setting is

received_header_text = Received: \
  ${if def:sender_rcvhost {from $sender_rcvhost\n\t}\
  {${if def:sender_ident \
  {from ${quote_local_part:$sender_ident} }}\
  ${if def:sender_helo_name {(helo=$sender_helo_name)\n\t}}}}\
  by $primary_hostname \
  ${if def:received_protocol {with $received_protocol}} \
  ${if def:tls_cipher {($tls_cipher)\n\t}}\
  (Exim $version_number)\n\t\
  ${if def:sender_address \
  {(envelope-from <$sender_address>)\n\t}}\
  id $message_exim_id\
  ${if def:received_for {\n\tfor $received_for}}

So you should be able to just paste the above text into your config, making whatever changes you'd like.