Santiago Romero wrote:
Postfix calls domains that it accepts mail for but delivers elsewhere
(such as MX backups) relay_domains. You can use a plain text file or
any supported postfix map type.
The list if valid recipients in those domains is specified in
relay_recipient_maps. Specify one or more map files listing the valid
recipients; all other recipients are rejected.
http://www.postfix.org/postconf.5.html#relay_recipient_maps
My question is : Can I have domains in relay_domains for which I check
relay_recipient_maps and domains for which I don't check it?
Example:
domain1.com -> My main domain, I know accounts in the primary MX
customer.com -> I work as MX backup for it, I don't know their accounts
relay_domains = domain1.com, customer.com
relay_recipient_maps = hash:/etc/postfix/valid_relay_accounts
If I define N (let's say 100) accounts for @domain1.com in
valid_relay_accounts and 0 accounts for @customer.com, what would
postfix do with with @customer.com emails? Would postfix reject or
accept it (no accounts defined in relay_recipient_maps por it).
My problem is that I have knowledge of accounts of SOME of the domains I
act as MXBackup for... and I want to "check rcpt to" only for those
domains, while accepting any RCPT TO for the others.
Thanks.
The link above says in part, "Specify @domain as a wild-card
for domains that have no valid recipient list, and become a
source of backscatter mail".
So a backscatter inducing wildcard entry would look like:
@example.com anything
You can use a check_recipient_access map that returns
reject_unverified_recipient for the domains that don't provide
a list to mitigate the problem.
http://www.postfix.org/ADDRESS_VERIFICATION_README.html#recipient
-- Noel Jones
